##############################################################################
###                                                                        ###
###           Full Paper (Acta Crystallographica Section C)                ###
###                                                                        ###
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#                                                                            #
# This CIF contains the data in a paper accepted for publication in Acta     #
# Crystallographica Section C. It conforms to the editorial and technical    #
# requirements of Notes for Authors for Section C, and has been peer         #
# reviewed under the auspices of the IUCr Commission on Journals.            #
#                                                                            #
# Full details of the Crystallographic Information File format               #
# are given in the paper "The Crystallographic Information File (CIF):       #
# a New Standard Archive File for Crystallography" by S. R. Hall, F. H.      #
# Allen and I. D. Brown [Acta Cryst. (1991), A47, 655-685].                  #
#                                                                            #
# The current version of the core CIF dictionary is obtainable from          #
# ftp://ftp.iucr.org/pub/cif_core.dic. The current version number is 2.0.1.  #
#                                                                            #
# Software is freely available for graphical display of the structure(s) in  #
# this CIF.  For information consult the CIF home page http://www.iucr.org/  #
# cif/home.html                                                              #
#                                                                            #
#            Copyright International Union of Crystallography                #
#                                                                            #
##############################################################################
data_I
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
bicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic anhydride
;
_chemical_name_common     ?
_chemical_formula_moiety     'C9 H8 O3'
_chemical_formula_sum     'C9 H8 O3'
_chemical_formula_weight     164.15
_chemical_melting_point     ?
_symmetry_cell_setting     Orthorhombic
_symmetry_space_group_name_H-M     'P 21 21 21'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    'x+1/2, -y+1/2, -z'
    '-x, y+1/2, -z+1/2'
    '-x+1/2, -y, z+1/2'
_cell_length_a     5.926(2)
_cell_length_b     9.489(3)
_cell_length_c     13.452(5)
_cell_angle_alpha     90
_cell_angle_beta     90
_cell_angle_gamma     90
_cell_volume     756.4(4)
_cell_formula_units_Z     4
_cell_measurement_reflns_used     7065
_cell_measurement_theta_min     1
_cell_measurement_theta_max     25
_cell_measurement_temperature     173(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .50
_exptl_crystal_size_mid      .40
_exptl_crystal_size_min      .18
_exptl_crystal_density_diffrn     1.441
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     344
_exptl_absorpt_coefficient_mu      .109
_exptl_absorpt_correction_type     empirical
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .948
_exptl_absorpt_correction_T_max      .981
_exptl_special_details
;
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     20569
_diffrn_reflns_av_R_equivalents      .037
_diffrn_reflns_av_sigmaI/netI      .012
_diffrn_reflns_theta_min     2.63
_diffrn_reflns_theta_max     28.69
_diffrn_reflns_theta_full     28.69
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -8
_diffrn_reflns_limit_h_max     8
_diffrn_reflns_limit_k_min     -12
_diffrn_reflns_limit_k_max     12
_diffrn_reflns_limit_l_min     -18
_diffrn_reflns_limit_l_max     18
_diffrn_standards_number     260
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     1440
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     1155
_reflns_number_gt     1082
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .043
_refine_ls_R_factor_gt      .041
_refine_ls_wR_factor_ref      .110
_refine_ls_goodness_of_fit_ref     1.138
_refine_ls_restrained_S_all     1.138
_refine_ls_number_reflns     1155
_refine_ls_number_parameters     109
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     constr
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
       'calc w = 1/[σ²(Fo²)+(0.0826P)²+0.0338P] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max     <0.001
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .35
_refine_diff_density_min      -.24
_refine_ls_extinction_method     none
_refine_ls_extinction_coef     ?
_refine_ls_abs_structure_details     ?
_refine_ls_abs_structure_Flack     ?
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .4506(3)  .38619(15)  .38354(11)  .0212(3) Uani d . 1 . . C
    H1  .5270  .2939  .3711  .025 Uiso calc R 1 . . H
    C2  .5923(3)  .48059(15)  .45206(11)  .0208(3) Uani d . 1 . . C
    H2  .7326  .4316  .4748  .025 Uiso calc R 1 . . H
    C3  .6486(3)  .61180(17)  .38476(12)  .0253(3) Uani d . 1 . . C
    H3  .7792  .6711  .4063  .030 Uiso calc R 1 . . H
    C4  .4273(4)  .68864(17)  .36767(13)  .0296(4) Uani d . 1 . . C
    H4  .3874  .7782  .3939  .036 Uiso calc R 1 . . H
    C5  .2991(3)  .60833(18)  .30933(13)  .0288(4) Uani d . 1 . . C
    H5  .1512  .6301  .2869  .035 Uiso calc R 1 . . H
    C6  .4315(3)  .47574(16)  .28505(12)  .0249(3) Uani d . 1 . . C
    H6  .3831  .4233  .2242  .030 Uiso calc R 1 . . H
    C7  .6743(3)  .53521(18)  .28384(12)  .0265(3) Uani d . 1 . . C
    H7A  .7016  .6007  .2278  .032 Uiso calc R 1 . . H
    H7B  .7910  .4606  .2851  .032 Uiso calc R 1 . . H
    C8  .2314(3)  .36648(16)  .43786(13)  .0246(3) Uani d . 1 . . C
    C9  .4384(3)  .51363(17)  .53771(12)  .0240(3) Uani d . 1 . . C
    O1  .2306(2)  .44609(13)  .52451(9)  .0276(3) Uani d . 1 . . O
    O2  .0700(2)  .29646(14)  .41689(11)  .0351(3) Uani d . 1 . . O
    O3  .4683(3)  .58680(15)  .60864(9)  .0352(4) Uani d . 1 . . O
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C8 . 1.502(2) ?
    C1 C2 . 1.535(2) ?
    C1 C6 . 1.578(2) ?
    C1 H1 . 1.0000 ?
    C2 C9 . 1.503(2) ?
    C2 C3 . 1.575(2) ?
    C2 H2 . 1.0000 ?
    C3 C4 . 1.518(3) ?
    C3 C7 . 1.547(2) ?
    C3 H3 . 1.0000 ?
    C4 C5 . 1.332(3) ?
    C4 H4 .  .9500 ?
    C5 C6 . 1.518(2) ?
    C5 H5 .  .9500 ?
    C6 C7 . 1.545(2) ?
    C6 H6 . 1.0000 ?
    C7 H7A .  .9900 ?
    C7 H7B .  .9900 ?
    C8 O2 . 1.198(2) ?
    C8 O1 . 1.389(2) ?
    C9 O3 . 1.193(2) ?
    C9 O1 . 1.400(2) ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C8 C1 C2 . . 104.69(13) ?
    C8 C1 C6 . . 114.41(14) ?
    C2 C1 C6 . . 103.24(12) ?
    C8 C1 H1 . . 111.3 ?
    C2 C1 H1 . . 111.3 ?
    C6 C1 H1 . . 111.3 ?
    C9 C2 C1 . . 104.48(13) ?
    C9 C2 C3 . . 113.84(13) ?
    C1 C2 C3 . . 103.41(12) ?
    C9 C2 H2 . . 111.5 ?
    C1 C2 H2 . . 111.5 ?
    C3 C2 H2 . . 111.5 ?
    C4 C3 C7 . . 100.25(14) ?
    C4 C3 C2 . . 106.51(13) ?
    C7 C3 C2 . . 98.85(12) ?
    C4 C3 H3 . . 116.2 ?
    C7 C3 H3 . . 116.2 ?
    C2 C3 H3 . . 116.2 ?
    C5 C4 C3 . . 107.89(14) ?
    C5 C4 H4 . . 126.1 ?
    C3 C4 H4 . . 126.1 ?
    C4 C5 C6 . . 107.82(16) ?
    C4 C5 H5 . . 126.1 ?
    C6 C5 H5 . . 126.1 ?
    C5 C6 C7 . . 100.42(13) ?
    C5 C6 C1 . . 107.62(13) ?
    C7 C6 C1 . . 97.96(13) ?
    C5 C6 H6 . . 116.1 ?
    C7 C6 H6 . . 116.1 ?
    C1 C6 H6 . . 116.1 ?
    C6 C7 C3 . . 94.05(13) ?
    C6 C7 H7A . . 112.9 ?
    C3 C7 H7A . . 112.9 ?
    C6 C7 H7B . . 112.9 ?
    C3 C7 H7B . . 112.9 ?
    H7A C7 H7B . . 110.3 ?
    O2 C8 O1 . . 119.75(16) ?
    O2 C8 C1 . . 130.15(16) ?
    O1 C8 C1 . . 110.09(14) ?
    O3 C9 O1 . . 119.88(16) ?
    O3 C9 C2 . . 130.14(16) ?
    O1 C9 C2 . . 109.96(13) ?
    C8 O1 C9 . . 110.63(13) ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C8 C1 C2 C9 . . . . -2.86(15) ?
    C6 C1 C2 C9 . . . . 117.18(13) ?
    C8 C1 C2 C3 . . . . -122.25(13) ?
    C6 C1 C2 C3 . . . . -2.21(15) ?
    C9 C2 C3 C4 . . . . -44.70(18) ?
    C1 C2 C3 C4 . . . . 68.03(15) ?
    C9 C2 C3 C7 . . . . -148.22(14) ?
    C1 C2 C3 C7 . . . . -35.49(15) ?
    C7 C3 C4 C5 . . . . 33.14(17) ?
    C2 C3 C4 C5 . . . . -69.37(16) ?
    C3 C4 C5 C6 . . . .  -.39(18) ?
    C4 C5 C6 C7 . . . . -32.57(17) ?
    C4 C5 C6 C1 . . . . 69.33(18) ?
    C8 C1 C6 C5 . . . . 48.63(18) ?
    C2 C1 C6 C5 . . . . -64.50(17) ?
    C8 C1 C6 C7 . . . . 152.28(13) ?
    C2 C1 C6 C7 . . . . 39.15(14) ?
    C5 C6 C7 C3 . . . . 49.16(15) ?
    C1 C6 C7 C3 . . . . -60.50(13) ?
    C4 C3 C7 C6 . . . . -49.33(14) ?
    C2 C3 C7 C6 . . . . 59.35(14) ?
    C2 C1 C8 O2 . . . . -176.41(17) ?
    C6 C1 C8 O2 . . . . 71.3(2) ?
    C2 C1 C8 O1 . . . . 3.91(16) ?
    C6 C1 C8 O1 . . . . -108.37(15) ?
    C1 C2 C9 O3 . . . . -177.39(17) ?
    C3 C2 C9 O3 . . . . -65.3(2) ?
    C1 C2 C9 O1 . . . . 1.01(16) ?
    C3 C2 C9 O1 . . . . 113.10(14) ?
    O2 C8 O1 C9 . . . . 176.83(14) ?
    C1 C8 O1 C9 . . . . -3.45(17) ?
    O3 C9 O1 C8 . . . . -179.94(15) ?
    C2 C9 O1 C8 . . . . 1.47(17) ?
data_II
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic
anhydride diethyl ether solvate
;
_chemical_name_common     ?
_chemical_formula_moiety     'C9 H2 Cl6 O3 , 0.16C4 H10 O'
_chemical_formula_sum     'C9 H2 Cl6 O3 , 0.16C4 H10 O'
_chemical_formula_weight     383.16
_chemical_melting_point     ?
_symmetry_cell_setting     Trigonal
_symmetry_space_group_name_H-M     R-3
_symmetry_space_group_name_Hall     '-R 3'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-y, x-y, z'
    '-x+y, -x, z'
    'x+2/3, y+1/3, z+1/3'
    '-y+2/3, x-y+1/3, z+1/3'
    '-x+y+2/3, -x+1/3, z+1/3'
    'x+1/3, y+2/3, z+2/3'
    '-y+1/3, x-y+2/3, z+2/3'
    '-x+y+1/3, -x+2/3, z+2/3'
    '-x, -y, -z'
    'y, -x+y, -z'
    'x-y, x, -z'
    '-x+2/3, -y+1/3, -z+1/3'
    'y+2/3, -x+y+1/3, -z+1/3'
    'x-y+2/3, x+1/3, -z+1/3'
    '-x+1/3, -y+2/3, -z+2/3'
    'y+1/3, -x+y+2/3, -z+2/3'
    'x-y+1/3, x+2/3, -z+2/3'
_cell_length_a     29.639(4)
_cell_length_b     29.639(4)
_cell_length_c     8.119(2)
_cell_angle_alpha     90
_cell_angle_beta     90
_cell_angle_gamma     120
_cell_volume     6176.8(19)
_cell_formula_units_Z     18
_cell_measurement_reflns_used     512
_cell_measurement_theta_min     1
_cell_measurement_theta_max     20
_cell_measurement_temperature     173(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .30
_exptl_crystal_size_mid      .20
_exptl_crystal_size_min      .15
_exptl_crystal_density_diffrn     1.854
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     3402
_exptl_absorpt_coefficient_mu     1.249
_exptl_absorpt_correction_type     empirical
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .706
_exptl_absorpt_correction_T_max      .835
_exptl_special_details
;
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     31306
_diffrn_reflns_av_R_equivalents      .045
_diffrn_reflns_av_sigmaI/netI      .022
_diffrn_reflns_theta_min     2.38
_diffrn_reflns_theta_max     26.37
_diffrn_reflns_theta_full     26.37
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -36
_diffrn_reflns_limit_h_max     37
_diffrn_reflns_limit_k_min     -37
_diffrn_reflns_limit_k_max     37
_diffrn_reflns_limit_l_min     -10
_diffrn_reflns_limit_l_max     10
_diffrn_standards_number     317
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     1800
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     2811
_reflns_number_gt     2314
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .046
_refine_ls_R_factor_gt      .032
_refine_ls_wR_factor_ref      .078
_refine_ls_goodness_of_fit_ref     1.060
_refine_ls_restrained_S_all     1.061
_refine_ls_number_reflns     2811
_refine_ls_number_parameters     173
_refine_ls_number_restraints     2
_refine_ls_hydrogen_treatment     constr
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
      'calc w = 1/[σ²(Fo²)+(0.0319P)²+19.3097P] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max      .001
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .73
_refine_diff_density_min      -.38
_refine_ls_extinction_method     none
_refine_ls_extinction_coef     ?
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Cl' 'Cl'  .1484  .1585
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .32288(9)  .40866(9)  .3739(3)  .0236(5) Uani d . 1 . . C
    H1  .3598  .4163  .3724  .028 Uiso calc R 1 . . H
    C2  .31361(9)  .44191(9)  .2488(3)  .0251(5) Uani d . 1 . . C
    H2  .3461  .4657  .1866  .030 Uiso calc R 1 . . H
    C3  .29484(10)  .47295(9)  .3578(3)  .0252(5) Uani d . 1 . . C
    Cl3  .29797(3)  .52706(3)  .26211(10)  .0464(2) Uani d . 1 . . Cl
    C4  .24234(9)  .43351(9)  .4300(3)  .0230(5) Uani d . 1 . . C
    Cl4  .18418(3)  .42570(3)  .36819(8)  .03901(18) Uani d . 1 . . Cl
    C5  .25017(9)  .40453(9)  .5379(3)  .0215(5) Uani d . 1 . . C
    Cl5  .20471(2)  .35140(3)  .64147(8)  .03192(16) Uani d . 1 . . Cl
    C6  .30830(9)  .42379(9)  .5416(3)  .0230(5) Uani d . 1 . . C
    Cl6  .33108(3)  .40670(3)  .71498(8)  .03710(17) Uani d . 1 . . Cl
    C7  .32971(9)  .48300(10)  .5122(3)  .0280(5) Uani d . 1 . . C
    Cl71  .39703(3)  .51862(3)  .46847(10)  .04236(19) Uani d . 1 . . Cl
    Cl72  .31643(3)  .51406(3)  .67495(9)  .03886(18) Uani d . 1 . . Cl
    C8  .28509(9)  .35302(10)  .3245(3)  .0242(5) Uani d . 1 . . C
    O2  .27761(7)  .31351(7)  .3867(2)  .0313(4) Uani d . 1 . . O
    C9  .27141(10)  .40316(10)  .1365(3)  .0260(5) Uani d . 1 . . C
    O3  .25089(8)  .40991(8)  .0220(2)  .0374(5) Uani d . 1 . . O
    O1  .25653(7)  .35263(6)  .1891(2)  .0270(4) Uani d . 1 . . O
    C11  .3617(6)  .6579(6)  .4546(18)  .092(4) Uiso d P  .33 . . C
    H11A  .3643  .6786  .5488  .138 Uiso d PR  .33 . . H
    H11B  .3435  .6217  .4846  .138 Uiso d PR  .33 . . H
    H11C  .3960  .6674  .4163  .138 Uiso d PR  .33 . . H
    C12  .3333  .6667  .3124(14)  .143(4) Uiso d SD 1 . . C
    H12A  .3514  .7031  .2861  .172 Uiso d PR  .33 . . H
    H12B  .2996  .6580  .3536  .172 Uiso d PR  .33 . . H
    O13  .327(4)  .6365(16)  .1648(11)  .117(8) Uiso d PD  .17 . . O
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C8 . 1.513(3) ?
    C1 C2 . 1.532(3) ?
    C1 C6 . 1.561(3) ?
    C1 H1 . 1.0000 ?
    C2 C9 . 1.509(3) ?
    C2 C3 . 1.565(3) ?
    C2 H2 . 1.0000 ?
    C3 C4 . 1.521(3) ?
    C3 C7 . 1.556(3) ?
    C3 Cl3 . 1.742(2) ?
    C4 C5 . 1.326(3) ?
    C4 Cl4 . 1.697(2) ?
    C5 C6 . 1.520(3) ?
    C5 Cl5 . 1.697(2) ?
    C6 C7 . 1.558(3) ?
    C6 Cl6 . 1.742(2) ?
    C7 Cl72 . 1.764(2) ?
    C7 Cl71 . 1.765(2) ?
    C8 O2 . 1.190(3) ?
    C8 O1 . 1.384(3) ?
    C9 O3 . 1.182(3) ?
    C9 O1 . 1.400(3) ?
    C11 C12 . 1.525(15) ?
    C11 H11A .  .9601 ?
    C11 H11B .  .9599 ?
    C11 H11C .  .9599 ?
    C12 O13 . 1.451(9) ?
    C12 H12A .  .9601 ?
    C12 H12B .  .9600 ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C8 C1 C2 . . 104.60(19) ?
    C8 C1 C6 . . 112.60(19) ?
    C2 C1 C6 . . 103.24(18) ?
    C8 C1 H1 . . 112.0 ?
    C2 C1 H1 . . 112.0 ?
    C6 C1 H1 . . 112.0 ?
    C9 C2 C1 . . 104.94(19) ?
    C9 C2 C3 . . 112.7(2) ?
    C1 C2 C3 . . 103.54(19) ?
    C9 C2 H2 . . 111.7 ?
    C1 C2 H2 . . 111.7 ?
    C3 C2 H2 . . 111.7 ?
    C4 C3 C7 . . 99.37(18) ?
    C4 C3 C2 . . 107.09(19) ?
    C7 C3 C2 . . 99.84(19) ?
    C4 C3 Cl3 . . 116.27(17) ?
    C7 C3 Cl3 . . 117.28(17) ?
    C2 C3 Cl3 . . 114.71(17) ?
    C5 C4 C3 . . 108.0(2) ?
    C5 C4 Cl4 . . 127.02(19) ?
    C3 C4 Cl4 . . 124.75(18) ?
    C4 C5 C6 . . 107.6(2) ?
    C4 C5 Cl5 . . 127.83(19) ?
    C6 C5 Cl5 . . 124.30(18) ?
    C5 C6 C7 . . 99.60(18) ?
    C5 C6 C1 . . 107.42(18) ?
    C7 C6 C1 . . 100.04(19) ?
    C5 C6 Cl6 . . 115.98(17) ?
    C7 C6 Cl6 . . 116.93(17) ?
    C1 C6 Cl6 . . 114.71(16) ?
    C3 C7 C6 . . 92.89(18) ?
    C3 C7 Cl72 . . 113.80(17) ?
    C6 C7 Cl72 . . 113.67(18) ?
    C3 C7 Cl71 . . 113.36(18) ?
    C6 C7 Cl71 . . 113.99(17) ?
    Cl72 C7 Cl71 . . 108.61(13) ?
    O2 C8 O1 . . 121.1(2) ?
    O2 C8 C1 . . 129.2(2) ?
    O1 C8 C1 . . 109.7(2) ?
    O3 C9 O1 . . 120.5(2) ?
    O3 C9 C2 . . 130.3(2) ?
    O1 C9 C2 . . 109.1(2) ?
    C8 O1 C9 . . 111.65(18) ?
    C12 C11 C11 . 3_565 55.5(5) ?
    C12 C11 C11 . 2_665 55.5(5) ?
    C11 C11 C11 3_565 2_665 60.002(4) ?
    C12 C11 H11A . . 111.7 ?
    C12 C11 H11B . . 109.4 ?
    H11A C11 H11B . . 109.5 ?
    C12 C11 H11C . . 107.3 ?
    H11A C11 H11C . . 109.5 ?
    H11B C11 H11C . . 109.5 ?
    O13 C12 C11 . . 115(3) ?
    O13 C12 H12A . . 109.7 ?
    C11 C12 H12A . . 108.4 ?
    O13 C12 H12B . . 109.3 ?
    C11 C12 H12B . . 106.3 ?
    H12A C12 H12B . . 107.5 ?
    C12 O13 C12 13_565 . 110.6(15) ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C8 C1 C2 C9 . . . .  -.2(2) ?
    C6 C1 C2 C9 . . . . -118.14(19) ?
    C8 C1 C2 C3 . . . . 118.2(2) ?
    C6 C1 C2 C3 . . . .  .2(2) ?
    C9 C2 C3 C4 . . . . 46.6(3) ?
    C1 C2 C3 C4 . . . . -66.2(2) ?
    C9 C2 C3 C7 . . . . 149.7(2) ?
    C1 C2 C3 C7 . . . . 36.9(2) ?
    C9 C2 C3 Cl3 . . . . -84.0(2) ?
    C1 C2 C3 Cl3 . . . . 163.17(16) ?
    C7 C3 C4 C5 . . . . -34.5(2) ?
    C2 C3 C4 C5 . . . . 68.9(2) ?
    Cl3 C3 C4 C5 . . . . -161.34(17) ?
    C7 C3 C4 Cl4 . . . . 150.29(18) ?
    C2 C3 C4 Cl4 . . . . -106.3(2) ?
    Cl3 C3 C4 Cl4 . . . . 23.5(3) ?
    C3 C4 C5 C6 . . . .  .2(2) ?
    Cl4 C4 C5 C6 . . . . 175.22(18) ?
    C3 C4 C5 Cl5 . . . . -174.04(18) ?
    Cl4 C4 C5 Cl5 . . . . 1.0(3) ?
    C4 C5 C6 C7 . . . . 34.2(2) ?
    Cl5 C5 C6 C7 . . . . -151.32(18) ?
    C4 C5 C6 C1 . . . . -69.6(2) ?
    Cl5 C5 C6 C1 . . . . 104.9(2) ?
    C4 C5 C6 Cl6 . . . . 160.62(17) ?
    Cl5 C5 C6 Cl6 . . . . -24.9(3) ?
    C8 C1 C6 C5 . . . . -46.0(3) ?
    C2 C1 C6 C5 . . . . 66.2(2) ?
    C8 C1 C6 C7 . . . . -149.5(2) ?
    C2 C1 C6 C7 . . . . -37.2(2) ?
    C8 C1 C6 Cl6 . . . . 84.5(2) ?
    C2 C1 C6 Cl6 . . . . -163.23(16) ?
    C4 C3 C7 C6 . . . . 51.21(19) ?
    C2 C3 C7 C6 . . . . -58.12(19) ?
    Cl3 C3 C7 C6 . . . . 177.35(17) ?
    C4 C3 C7 Cl72 . . . . -66.3(2) ?
    C2 C3 C7 Cl72 . . . . -175.61(16) ?
    Cl3 C3 C7 Cl72 . . . . 59.9(2) ?
    C4 C3 C7 Cl71 . . . . 168.94(16) ?
    C2 C3 C7 Cl71 . . . . 59.6(2) ?
    Cl3 C3 C7 Cl71 . . . . -64.9(2) ?
    C5 C6 C7 C3 . . . . -51.29(19) ?
    C1 C6 C7 C3 . . . . 58.49(19) ?
    Cl6 C6 C7 C3 . . . . -177.04(16) ?
    C5 C6 C7 Cl72 . . . . 66.3(2) ?
    C1 C6 C7 Cl72 . . . . 176.08(16) ?
    Cl6 C6 C7 Cl72 . . . . -59.4(2) ?
    C5 C6 C7 Cl71 . . . . -168.49(16) ?
    C1 C6 C7 Cl71 . . . . -58.7(2) ?
    Cl6 C6 C7 Cl71 . . . . 65.8(2) ?
    C2 C1 C8 O2 . . . . -179.0(2) ?
    C6 C1 C8 O2 . . . . -67.6(3) ?
    C2 C1 C8 O1 . . . .  -.5(2) ?
    C6 C1 C8 O1 . . . . 110.9(2) ?
    C1 C2 C9 O3 . . . . 179.5(3) ?
    C3 C2 C9 O3 . . . . 67.5(3) ?
    C1 C2 C9 O1 . . . .  .8(2) ?
    C3 C2 C9 O1 . . . . -111.2(2) ?
    O2 C8 O1 C9 . . . . 179.6(2) ?
    C1 C8 O1 C9 . . . . 1.0(3) ?
    O3 C9 O1 C8 . . . . 180.0(2) ?
    C2 C9 O1 C8 . . . . -1.1(3) ?
    C11 C12 O13 C12 . . . 13_565 -142(5) ?
    C11 C12 O13 C12 3_565 . . 13_565 140(5) ?
data_III
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
bicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid
;
_chemical_name_common     ?
_chemical_formula_moiety     'C9 H10 O4'
_chemical_formula_sum     'C9 H10 O4'
_chemical_formula_weight     182.17
_chemical_melting_point     ?
_symmetry_cell_setting     Monoclinic
_symmetry_space_group_name_H-M     'P 21/c'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x, y+1/2, -z+1/2'
    '-x, -y, -z'
    'x, -y-1/2, z-1/2'
_cell_length_a     10.999(2)
_cell_length_b     7.3890(10)
_cell_length_c     10.410(2)
_cell_angle_alpha     90
_cell_angle_beta     98.75(3)
_cell_angle_gamma     90
_cell_volume     836.2(2)
_cell_formula_units_Z     4
_cell_measurement_reflns_used     4135
_cell_measurement_theta_min     0
_cell_measurement_theta_max     25
_cell_measurement_temperature     173(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .5
_exptl_crystal_size_mid      .1
_exptl_crystal_size_min      .1
_exptl_crystal_density_diffrn     1.447
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     384
_exptl_absorpt_coefficient_mu      .115
_exptl_absorpt_correction_type     'empirical'
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .945
_exptl_absorpt_correction_T_max      .989
_exptl_special_details
;
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     12009
_diffrn_reflns_av_R_equivalents      .062
_diffrn_reflns_av_sigmaI/netI      .036
_diffrn_reflns_theta_min     1.87
_diffrn_reflns_theta_max     26.37
_diffrn_reflns_theta_full     26.37
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -13
_diffrn_reflns_limit_h_max     13
_diffrn_reflns_limit_k_min     -9
_diffrn_reflns_limit_k_max     9
_diffrn_reflns_limit_l_min     -13
_diffrn_reflns_limit_l_max     13
_diffrn_standards_number     116
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     960
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     1707
_reflns_number_gt     1304
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .079
_refine_ls_R_factor_gt      .059
_refine_ls_wR_factor_ref      .152
_refine_ls_goodness_of_fit_ref     1.095
_refine_ls_restrained_S_all     1.095
_refine_ls_number_reflns     1707
_refine_ls_number_parameters     121
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     mixed
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
       'calc w = 1/[σ²(Fo²)+(0.0499P)²+1.4698P] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max     <0.001
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .28
_refine_diff_density_min      -.28
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_extinction_coef      .021(4)
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .1539(2)  .7981(4)  .3321(2)  .0199(6) Uani d . 1 . . C
    H1  .1085  .7814  .2421  .024 Uiso calc R 1 . . H
    C11  .1000(2)  .6637(4)  .4161(3)  .0208(6) Uani d . 1 . . C
    O11  .04417(18)  .7081(3)  .50377(19)  .0280(5) Uani d . 1 . . O
    O12  .10889(19)  .4943(3)  .3781(2)  .0294(5) Uani d . 1 . . O
    H12  .0700  .4266  .4224  .035 Uiso calc R 1 . . H
    C2  .2941(2)  .7881(4)  .3204(3)  .0229(6) Uani d . 1 . . C
    H2  .3018  .7641  .2275  .028 Uiso calc R 1 . . H
    C21  .3751(2)  .6575(4)  .4033(3)  .0237(6) Uani d . 1 . . C
    O21  .36102(19)  .6043(3)  .51021(19)  .0344(6) Uani d . 1 . . O
    O22  .4710(2)  .6116(4)  .3478(2)  .0473(7) Uani d . 1 . . O
    H22  .5214  .5535  .4011  .057 Uiso calc R 1 . . H
    C3  .3360(3)  .9902(4)  .3534(3)  .0274(7) Uani d . 1 . . C
    H3  .4161 1.0272  .3270  .033 Uiso calc R 1 . . H
    C4  .3234(3) 1.0230(4)  .4945(3)  .0306(7) Uani d . 1 . . C
    H4  .3891 1.0365  .5644  .037 Uiso calc R 1 . . H
    C5  .2050(3) 1.0295(4)  .5032(3)  .0259(6) Uani d . 1 . . C
    H5  .1702 1.0495  .5801  .031 Uiso calc R 1 . . H
    C6  .1348(2)  .9992(4)  .3684(3)  .0233(6) Uani d . 1 . . C
    H6  .0478 1.0431  .3539  .028 Uiso calc R 1 . . H
    C7  .2215(3) 1.0907(4)  .2860(3)  .0293(7) Uani d . 1 . . C
    H7A  .2268 1.2234  .2989  .035 Uiso calc R 1 . . H
    H7B  .2014 1.0616  .1924  .035 Uiso calc R 1 . . H
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C11 . 1.503(4) ?
    C1 C6 . 1.555(4) ?
    C1 C2 . 1.567(4) ?
    C1 H1 . 1.0000 ?
    C11 O11 . 1.220(3) ?
    C11 O12 . 1.320(3) ?
    O12 H12 .  .8400 ?
    C2 C21 . 1.495(4) ?
    C2 C3 . 1.585(4) ?
    C2 H2 . 1.0000 ?
    C21 O21 . 1.213(3) ?
    C21 O22 . 1.322(3) ?
    O22 H22 .  .8400 ?
    C3 C4 . 1.516(4) ?
    C3 C7 . 1.536(4) ?
    C3 H3 . 1.0000 ?
    C4 C5 . 1.320(4) ?
    C4 H4 .  .9500 ?
    C5 C6 . 1.511(4) ?
    C5 H5 .  .9500 ?
    C6 C7 . 1.533(4) ?
    C6 H6 . 1.0000 ?
    C7 H7A .  .9900 ?
    C7 H7B .  .9900 ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C11 C1 C6 . . 114.2(2) ?
    C11 C1 C2 . . 119.6(2) ?
    C6 C1 C2 . . 103.6(2) ?
    C11 C1 H1 . . 106.2 ?
    C6 C1 H1 . . 106.2 ?
    C2 C1 H1 . . 106.2 ?
    O11 C11 O12 . . 123.2(3) ?
    O11 C11 C1 . . 123.0(2) ?
    O12 C11 C1 . . 113.5(2) ?
    C11 O12 H12 . . 109.5 ?
    C21 C2 C1 . . 119.5(2) ?
    C21 C2 C3 . . 110.8(2) ?
    C1 C2 C3 . . 101.3(2) ?
    C21 C2 H2 . . 108.2 ?
    C1 C2 H2 . . 108.2 ?
    C3 C2 H2 . . 108.2 ?
    O21 C21 O22 . . 122.7(3) ?
    O21 C21 C2 . . 126.2(2) ?
    O22 C21 C2 . . 111.0(2) ?
    C21 O22 H22 . . 109.5 ?
    C4 C3 C7 . . 100.1(2) ?
    C4 C3 C2 . . 107.1(2) ?
    C7 C3 C2 . . 99.5(2) ?
    C4 C3 H3 . . 115.9 ?
    C7 C3 H3 . . 115.9 ?
    C2 C3 H3 . . 115.9 ?
    C5 C4 C3 . . 108.0(3) ?
    C5 C4 H4 . . 126.0 ?
    C3 C4 H4 . . 126.0 ?
    C4 C5 C6 . . 107.5(3) ?
    C4 C5 H5 . . 126.2 ?
    C6 C5 H5 . . 126.2 ?
    C5 C6 C7 . . 100.4(2) ?
    C5 C6 C1 . . 107.3(2) ?
    C7 C6 C1 . . 99.6(2) ?
    C5 C6 H6 . . 115.7 ?
    C7 C6 H6 . . 115.7 ?
    C1 C6 H6 . . 115.7 ?
    C6 C7 C3 . . 93.9(2) ?
    C6 C7 H7A . . 112.9 ?
    C3 C7 H7A . . 112.9 ?
    C6 C7 H7B . . 112.9 ?
    C3 C7 H7B . . 112.9 ?
    H7A C7 H7B . . 110.4 ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C6 C1 C11 O11 . . . . 1.3(4) ?
    C2 C1 C11 O11 . . . . 124.7(3) ?
    C6 C1 C11 O12 . . . . 175.2(2) ?
    C2 C1 C11 O12 . . . . -61.3(3) ?
    C11 C1 C2 C21 . . . . -6.2(4) ?
    C6 C1 C2 C21 . . . . 122.3(3) ?
    C11 C1 C2 C3 . . . . -128.2(2) ?
    C6 C1 C2 C3 . . . .  .3(2) ?
    C1 C2 C21 O21 . . . . -29.4(4) ?
    C3 C2 C21 O21 . . . . 87.7(4) ?
    C1 C2 C21 O22 . . . . 154.0(3) ?
    C3 C2 C21 O22 . . . . -88.9(3) ?
    C21 C2 C3 C4 . . . . -61.5(3) ?
    C1 C2 C3 C4 . . . . 66.3(2) ?
    C21 C2 C3 C7 . . . . -165.3(2) ?
    C1 C2 C3 C7 . . . . -37.5(2) ?
    C7 C3 C4 C5 . . . . 32.6(3) ?
    C2 C3 C4 C5 . . . . -70.8(3) ?
    C3 C4 C5 C6 . . . .  .6(3) ?
    C4 C5 C6 C7 . . . . -33.7(3) ?
    C4 C5 C6 C1 . . . . 70.0(3) ?
    C11 C1 C6 C5 . . . . 64.6(3) ?
    C2 C1 C6 C5 . . . . -67.2(3) ?
    C11 C1 C6 C7 . . . . 168.8(2) ?
    C2 C1 C6 C7 . . . . 37.0(3) ?
    C5 C6 C7 C3 . . . . 49.9(3) ?
    C1 C6 C7 C3 . . . . -59.9(2) ?
    C4 C3 C7 C6 . . . . -49.3(3) ?
    C2 C3 C7 C6 . . . . 60.1(2) ?
loop_
    _geom_hbond_atom_site_label_D
    _geom_hbond_atom_site_label_H
    _geom_hbond_atom_site_label_A
    _geom_hbond_site_symmetry_A
    _geom_hbond_distance_DH
    _geom_hbond_distance_HA
    _geom_hbond_distance_DA
    _geom_hbond_angle_DHA
    O12 H12 O11 3_566  .84 1.86 2.685(3) 168.1
    O22 H22 O21 3_666  .84 1.88 2.704(3) 168.1
data_IVa
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid
;
_chemical_name_common     ?
_chemical_formula_moiety     'C9 H4 Cl6 O4'
_chemical_formula_sum     'C9 H4 Cl6 O4'
_chemical_formula_weight     388.82
_chemical_melting_point     ?
_symmetry_cell_setting     Monoclinic
_symmetry_space_group_name_H-M     'P 21'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x, y+1/2, -z'
_cell_length_a     7.4990(10)
_cell_length_b     7.924(2)
_cell_length_c     11.873(2)
_cell_angle_alpha     90
_cell_angle_beta     101.650(10)
_cell_angle_gamma     90
_cell_volume     691.0(2)
_cell_formula_units_Z     2
_cell_measurement_reflns_used     511
_cell_measurement_theta_min     1
_cell_measurement_theta_max     25
_cell_measurement_temperature     173(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .40
_exptl_crystal_size_mid      .30
_exptl_crystal_size_min      .15
_exptl_crystal_density_diffrn     1.869
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     384
_exptl_absorpt_coefficient_mu     1.246
_exptl_absorpt_correction_type     'empirical'
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .636
_exptl_absorpt_correction_T_max      .835
_exptl_special_details
;
 ?
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     19175
_diffrn_reflns_av_R_equivalents      .025
_diffrn_reflns_av_sigmaI/netI      .017
_diffrn_reflns_theta_min     1.75
_diffrn_reflns_theta_max     28.28
_diffrn_reflns_theta_full     28.28
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -9
_diffrn_reflns_limit_h_max     9
_diffrn_reflns_limit_k_min     -10
_diffrn_reflns_limit_k_max     10
_diffrn_reflns_limit_l_min     -15
_diffrn_reflns_limit_l_max     15
_diffrn_standards_number     325
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     1200
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     3424
_reflns_number_gt     3293
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .020
_refine_ls_R_factor_gt      .019
_refine_ls_wR_factor_ref      .048
_refine_ls_goodness_of_fit_ref     1.044
_refine_ls_restrained_S_all     1.044
_refine_ls_number_reflns     3424
_refine_ls_number_parameters     180
_refine_ls_number_restraints     1
_refine_ls_hydrogen_treatment     mixed
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
         'calc w = 1/[σ²(Fo²)+(0.03P)²+0.0924P] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max      .001
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .28
_refine_diff_density_min      -.21
_refine_ls_extinction_method     none
_refine_ls_extinction_coef     ?
_refine_ls_abs_structure_details     'Flack (1983)'
_refine_ls_abs_structure_Flack      .02(4)
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Cl' 'Cl'  .1484  .1585
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .69443(18)  .56656(19)  .66518(12)  .0136(3) Uani d . 1 . . C
    H1  .5763  .5043  .6443  .016 Uiso calc R 1 . . H
    C11  .8403(2)  .45674(19)  .62955(13)  .0157(3) Uani d . 1 . . C
    O11  .99048(15)  .42735(15)  .68550(9)  .0197(2) Uani d . 1 . . O
    O12  .77577(16)  .39949(16)  .52437(10)  .0242(3) Uani d . 1 . . O
    H12  .854(3)  .356(3)  .500(2)  .034(6) Uiso d . 1 . . H
    C2  .66776(19)  .74293(18)  .60301(12)  .0147(3) Uani d . 1 . . C
    H2  .5418  .7502  .5554  .018 Uiso calc R 1 . . H
    C21  .8045(2)  .78274(19)  .52874(14)  .0164(3) Uani d . 1 . . C
    O21  .96690(15)  .75069(17)  .55919(11)  .0253(3) Uani d . 1 . . O
    O22  .73263(16)  .85559(18)  .43038(10)  .0252(3) Uani d . 1 . . O
    H22  .815(4)  .866(4)  .394(2)  .055(8) Uiso d . 1 . . H
    C3  .6853(2)  .86596(19)  .70806(13)  .0169(3) Uani d . 1 . . C
    Cl3  .59753(6) 1.06861(5)  .67095(4)  .02737(9) Uani d . 1 . . Cl
    C4  .8791(2)  .8599(2)  .77924(13)  .0179(3) Uani d . 1 . . C
    Cl4 1.03082(6) 1.02032(5)  .78540(4)  .02851(10) Uani d . 1 . . Cl
    C5  .90148(19)  .7098(2)  .83183(12)  .0177(3) Uani d . 1 . . C
    Cl5 1.08377(5)  .63452(6)  .92641(3)  .02633(9) Uani d . 1 . . Cl
    C6  .7233(2)  .61224(19)  .79471(13)  .0163(3) Uani d . 1 . . C
    Cl6  .68870(6)  .44331(5)  .88242(4)  .02736(9) Uani d . 1 . . Cl
    C7  .5867(2)  .7625(2)  .78891(13)  .0181(3) Uani d . 1 . . C
    Cl71  .35827(5)  .70969(5)  .72692(3)  .02249(9) Uani d . 1 . . Cl
    Cl72  .58781(6)  .86019(6)  .92252(4)  .02939(10) Uani d . 1 . . Cl
loop_
    _atom_site_aniso_label
    _atom_site_aniso_U_11
    _atom_site_aniso_U_22
    _atom_site_aniso_U_33
    _atom_site_aniso_U_12
    _atom_site_aniso_U_13
    _atom_site_aniso_U_23
    C1  .0126(6)  .0134(6)  .0160(6)  -.0002(5)  .0055(5)  -.0003(5)
    C11  .0181(7)  .0121(6)  .0189(7)  -.0018(5)  .0083(6)  -.0005(6)
    O11  .0187(5)  .0206(5)  .0202(5)  .0040(5)  .0049(4)  .0004(5)
    O12  .0159(5)  .0322(7)  .0244(6)  .0045(5)  .0039(5)  -.0116(5)
    C2  .0140(6)  .0144(7)  .0166(7)  .0002(5)  .0048(5)  .0006(5)
    C21  .0174(7)  .0144(6)  .0180(7)  -.0009(5)  .0052(5)  .0022(5)
    O21  .0151(5)  .0350(7)  .0268(6)  .0003(5)  .0068(4)  .0113(5)
    O22  .0192(5)  .0369(7)  .0204(6)  .0022(5)  .0059(5)  .0131(5)
    C3  .0169(7)  .0130(6)  .0212(7)  .0006(5)  .0049(6)  -.0010(6)
    Cl3  .0289(2)  .01399(17)  .0380(2)  .00485(15)  .00408(17)  -.00003(16)
    C4  .0159(7)  .0182(7)  .0201(7)  -.0022(6)  .0046(5)  -.0040(6)
    Cl4  .02409(19)  .02241(18)  .0388(2)  -.00978(15)  .00585(16)  -.00508(17)
    C5  .0169(7)  .0217(7)  .0152(6)  .0001(6)  .0045(5)  -.0015(6)
    Cl5  .02127(17)  .0369(2)  .01900(18)  .00374(17)  -.00037(14)  .00260(16)
    C6  .0181(7)  .0160(7)  .0164(6)  -.0005(6)  .0075(5)  .0015(5)
    Cl6  .0347(2)  .02510(19)  .0254(2)  -.00138(17)  .01352(16)  .00918(17)
    C7  .0173(7)  .0201(7)  .0184(7)  -.0006(6)  .0073(6)  -.0042(6)
    Cl71  .01438(15)  .02752(19)  .02752(19)  -.00098(14)  .00888(13)
                                                                     -.00406(16)
    Cl72  .0298(2)  .0371(2)  .0242(2)  -.00039(18)  .01248(16)  -.01302(18)
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C11 . 1.523(2) ?
    C1 C6 . 1.552(2) ?
    C1 C2 . 1.574(2) ?
    C1 H1 . 1.0000 ?
    C11 O11 . 1.2087(19) ?
    C11 O12 . 1.3250(19) ?
    O12 H12 .  .79(2) ?
    C2 C21 . 1.515(2) ?
    C2 C3 . 1.568(2) ?
    C2 H2 . 1.0000 ?
    C21 O21 . 1.2249(19) ?
    C21 O22 . 1.3165(19) ?
    O22 H22 .  .83(3) ?
    C3 C4 . 1.527(2) ?
    C3 C7 . 1.558(2) ?
    C3 Cl3 . 1.7576(16) ?
    C4 C5 . 1.338(2) ?
    C4 Cl4 . 1.6978(16) ?
    C5 C6 . 1.530(2) ?
    C5 Cl5 . 1.6928(15) ?
    C6 C7 . 1.563(2) ?
    C6 Cl6 . 1.7471(16) ?
    C7 Cl72 . 1.7635(16) ?
    C7 Cl71 . 1.7725(16) ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C11 C1 C6 . . 116.37(12) ?
    C11 C1 C2 . . 114.03(11) ?
    C6 C1 C2 . . 103.69(11) ?
    C11 C1 H1 . . 107.4 ?
    C6 C1 H1 . . 107.4 ?
    C2 C1 H1 . . 107.4 ?
    O11 C11 O12 . . 125.07(14) ?
    O11 C11 C1 . . 126.80(13) ?
    O12 C11 C1 . . 108.12(12) ?
    C11 O12 H12 . . 109.8(17) ?
    C21 C2 C3 . . 112.07(12) ?
    C21 C2 C1 . . 114.90(12) ?
    C3 C2 C1 . . 101.35(11) ?
    C21 C2 H2 . . 109.4 ?
    C3 C2 H2 . . 109.4 ?
    C1 C2 H2 . . 109.4 ?
    O21 C21 O22 . . 123.87(14) ?
    O21 C21 C2 . . 122.31(14) ?
    O22 C21 C2 . . 113.81(13) ?
    C21 O22 H22 . . 107(2) ?
    C4 C3 C7 . . 99.17(12) ?
    C4 C3 C2 . . 109.79(12) ?
    C7 C3 C2 . . 100.90(12) ?
    C4 C3 Cl3 . . 115.71(11) ?
    C7 C3 Cl3 . . 115.77(11) ?
    C2 C3 Cl3 . . 113.69(10) ?
    C5 C4 C3 . . 107.57(13) ?
    C5 C4 Cl4 . . 128.72(12) ?
    C3 C4 Cl4 . . 123.71(12) ?
    C4 C5 C6 . . 107.14(13) ?
    C4 C5 Cl5 . . 129.14(12) ?
    C6 C5 Cl5 . . 123.69(12) ?
    C5 C6 C1 . . 110.01(12) ?
    C5 C6 C7 . . 98.88(12) ?
    C1 C6 C7 . . 100.08(12) ?
    C5 C6 Cl6 . . 116.20(11) ?
    C1 C6 Cl6 . . 113.84(11) ?
    C7 C6 Cl6 . . 115.79(10) ?
    C3 C7 C6 . . 92.27(11) ?
    C3 C7 Cl72 . . 114.00(11) ?
    C6 C7 Cl72 . . 114.25(11) ?
    C3 C7 Cl71 . . 114.05(11) ?
    C6 C7 Cl71 . . 114.08(11) ?
    Cl72 C7 Cl71 . . 107.81(8) ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C6 C1 C11 O11 . . . . -14.7(2) ?
    C2 C1 C11 O11 . . . . 105.94(17) ?
    C6 C1 C11 O12 . . . . 166.21(12) ?
    C2 C1 C11 O12 . . . . -73.11(16) ?
    C11 C1 C2 C21 . . . . -6.57(18) ?
    C6 C1 C2 C21 . . . . 120.97(13) ?
    C11 C1 C2 C3 . . . . -127.61(12) ?
    C6 C1 C2 C3 . . . .  -.08(13) ?
    C3 C2 C21 O21 . . . . 73.26(19) ?
    C1 C2 C21 O21 . . . . -41.7(2) ?
    C3 C2 C21 O22 . . . . -106.09(15) ?
    C1 C2 C21 O22 . . . . 138.93(14) ?
    C21 C2 C3 C4 . . . . -56.69(16) ?
    C1 C2 C3 C4 . . . . 66.32(14) ?
    C21 C2 C3 C7 . . . . -160.69(12) ?
    C1 C2 C3 C7 . . . . -37.68(13) ?
    C21 C2 C3 Cl3 . . . . 74.70(14) ?
    C1 C2 C3 Cl3 . . . . -162.29(10) ?
    C7 C3 C4 C5 . . . . 34.81(15) ?
    C2 C3 C4 C5 . . . . -70.36(16) ?
    Cl3 C3 C4 C5 . . . . 159.32(12) ?
    C7 C3 C4 Cl4 . . . . -145.45(12) ?
    C2 C3 C4 Cl4 . . . . 109.39(14) ?
    Cl3 C3 C4 Cl4 . . . . -20.94(18) ?
    C3 C4 C5 C6 . . . .  .89(17) ?
    Cl4 C4 C5 C6 . . . . -178.83(12) ?
    C3 C4 C5 Cl5 . . . . -176.88(12) ?
    Cl4 C4 C5 Cl5 . . . . 3.4(2) ?
    C4 C5 C6 C1 . . . . 68.10(16) ?
    Cl5 C5 C6 C1 . . . . -113.98(13) ?
    C4 C5 C6 C7 . . . . -36.11(15) ?
    Cl5 C5 C6 C7 . . . . 141.81(12) ?
    C4 C5 C6 Cl6 . . . . -160.70(11) ?
    Cl5 C5 C6 Cl6 . . . . 17.22(17) ?
    C11 C1 C6 C5 . . . . 60.22(17) ?
    C2 C1 C6 C5 . . . . -65.85(14) ?
    C11 C1 C6 C7 . . . . 163.61(12) ?
    C2 C1 C6 C7 . . . . 37.55(13) ?
    C11 C1 C6 Cl6 . . . . -72.21(14) ?
    C2 C1 C6 Cl6 . . . . 161.72(9) ?
    C4 C3 C7 C6 . . . . -52.81(13) ?
    C2 C3 C7 C6 . . . . 59.55(12) ?
    Cl3 C3 C7 C6 . . . . -177.27(10) ?
    C4 C3 C7 Cl72 . . . . 65.07(13) ?
    C2 C3 C7 Cl72 . . . . 177.42(10) ?
    Cl3 C3 C7 Cl72 . . . . -59.40(14) ?
    C4 C3 C7 Cl71 . . . . -170.51(10) ?
    C2 C3 C7 Cl71 . . . . -58.15(13) ?
    Cl3 C3 C7 Cl71 . . . . 65.03(14) ?
    C5 C6 C7 C3 . . . . 53.28(12) ?
    C1 C6 C7 C3 . . . . -59.02(12) ?
    Cl6 C6 C7 C3 . . . . 178.16(10) ?
    C5 C6 C7 Cl72 . . . . -64.38(13) ?
    C1 C6 C7 Cl72 . . . . -176.68(10) ?
    Cl6 C6 C7 Cl72 . . . . 60.50(14) ?
    C5 C6 C7 Cl71 . . . . 170.95(10) ?
    C1 C6 C7 Cl71 . . . . 58.65(13) ?
    Cl6 C6 C7 Cl71 . . . . -64.16(14) ?
loop_
    _geom_hbond_atom_site_label_D
    _geom_hbond_atom_site_label_H
    _geom_hbond_atom_site_label_A
    _geom_hbond_site_symmetry_A
    _geom_hbond_distance_DH
    _geom_hbond_distance_HA
    _geom_hbond_distance_DA
    _geom_hbond_angle_DHA
    O12 H12 O21 2_746  .79(2) 1.83(3) 2.6214(17) 179(3)
    O22 H22 O11 2_756  .83(3) 1.95(3) 2.7716(17) 171(3)
data_IVb
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
1,2,3,4,7,7-hexachlorobicyclo[2.2.1]hept-2-ene-endo-cis-5,6-dicarboxylic acid
;
_chemical_name_common     ?
_chemical_formula_moiety     'C9 H4 Cl6 O4'
_chemical_formula_sum     'C9 H4 Cl6 O4'
_chemical_formula_weight     388.82
_chemical_melting_point     ?
_symmetry_cell_setting     Monoclinic
_symmetry_space_group_name_H-M     'P 21/c '
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x, y+1/2, -z+1/2'
    '-x, -y, -z'
    'x, -y-1/2, z-1/2'
_cell_length_a     8.4430(10)
_cell_length_b     24.8090(10)
_cell_length_c     13.5940(10)
_cell_angle_alpha     90
_cell_angle_beta     90.380(10)
_cell_angle_gamma     90
_cell_volume     2847.4(4)
_cell_formula_units_Z     8
_cell_measurement_reflns_used     8192
_cell_measurement_theta_min     1
_cell_measurement_theta_max     25
_cell_measurement_temperature     173(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .5
_exptl_crystal_size_mid      .4
_exptl_crystal_size_min      .4
_exptl_crystal_density_diffrn     1.814
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     1536
_exptl_absorpt_coefficient_mu     1.209
_exptl_absorpt_correction_type     'empirical'
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .583
_exptl_absorpt_correction_T_max      .643
_exptl_special_details
;
 ?
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     61228
_diffrn_reflns_av_R_equivalents      .022
_diffrn_reflns_av_sigmaI/netI      .012
_diffrn_reflns_theta_min     1.71
_diffrn_reflns_theta_max     28.28
_diffrn_reflns_theta_full     28.28
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -11
_diffrn_reflns_limit_h_max     11
_diffrn_reflns_limit_k_min     -33
_diffrn_reflns_limit_k_max     33
_diffrn_reflns_limit_l_min     -18
_diffrn_reflns_limit_l_max     18
_diffrn_standards_number     943
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     1000
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     7069
_reflns_number_gt     6477
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .030
_refine_ls_R_factor_gt      .026
_refine_ls_wR_factor_ref      .061
_refine_ls_goodness_of_fit_ref     1.142
_refine_ls_restrained_S_all     1.142
_refine_ls_number_reflns     7069
_refine_ls_number_parameters     359
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     mixed
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
       'calc w = 1/[σ²(Fo²)+(0.0212P)²+2.1579P] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max      .002
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .35
_refine_diff_density_min      -.27
_refine_ls_extinction_method     none
_refine_ls_extinction_coef     ?
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Cl' 'Cl'  .1484  .1585
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .40303(17)  .57589(6)  .05060(10)  .0152(3) Uani d . 1 . . C
    H1  .3967  .5592  -.0163  .018 Uiso calc R 1 . . H
    C11  .31014(19)  .54093(6)  .12113(11)  .0183(3) Uani d . 1 . . C
    O11  .20251(15)  .55721(5)  .17186(10)  .0281(3) Uani d . 1 . . O
    O12  .36090(16)  .49070(5)  .12002(9)  .0266(3) Uani d . 1 . . O
    H12  .312(4)  .4732(12)  .158(2)  .065(9) Uiso d . 1 . . H
    C2  .58295(18)  .58333(6)  .07849(11)  .0164(3) Uani d . 1 . . C
    H2  .6469  .5730  .0198  .020 Uiso calc R 1 . . H
    C21  .64166(19)  .55000(6)  .16492(11)  .0199(3) Uani d . 1 . . C
    O21  .60277(16)  .55752(5)  .25014(8)  .0289(3) Uani d . 1 . . O
    O22  .73663(17)  .51146(6)  .13545(10)  .0319(3) Uani d . 1 . . O
    H22  .761(3)  .4947(12)  .180(2)  .062(9) Uiso d . 1 . . H
    C3  .59588(17)  .64548(6)  .09100(11)  .0161(3) Uani d . 1 . . C
    Cl3  .79204(5)  .668329(19)  .09327(3)  .02970(9) Uani d . 1 . . Cl
    C4  .49067(18)  .66525(6)  .17445(11)  .0178(3) Uani d . 1 . . C
    Cl4  .56021(5)  .692073(19)  .28104(3)  .03112(10) Uani d . 1 . . Cl
    C5  .34005(18)  .66042(6)  .14541(11)  .0165(3) Uani d . 1 . . C
    Cl5  .17543(5)  .681273(17)  .20501(3)  .02577(9) Uani d . 1 . . Cl
    C6  .34183(17)  .63490(6)  .04291(10)  .0142(3) Uani d . 1 . . C
    Cl6  .16874(5)  .641385(16)  -.02796(3)  .02392(8) Uani d . 1 . . Cl
    C7  .49143(18)  .66422(6)  .00175(11)  .0154(3) Uani d . 1 . . C
    Cl71  .55830(5)  .640423(15)  -.11362(3)  .02192(8) Uani d . 1 . . Cl
    Cl72  .46621(5)  .734510(15)  -.00749(3)  .02487(9) Uani d . 1 . . Cl
    C1A  .90607(17)  .57664(6)  .58458(11)  .0158(3) Uani d . 1 . . C
    H1A  .8400  .5626  .5289  .019 Uiso calc R 1 . . H
    C11A  .85269(19)  .54735(6)  .67609(11)  .0200(3) Uani d . 1 . . C
    O11A  .78471(15)  .56857(5)  .74461(9)  .0263(3) Uani d . 1 . . O
    O12A  .88191(17)  .49534(5)  .66866(10)  .0309(3) Uani d . 1 . . O
    H12A  .854(3)  .4793(12)  .719(2)  .063(9) Uiso d . 1 . . H
    C2A 1.08377(17)  .56819(6)  .55473(10)  .0154(3) Uani d . 1 . . C
    H2A 1.0887  .5480  .4912  .019 Uiso calc R 1 . . H
    C21A 1.18283(19)  .53924(6)  .63230(11)  .0187(3) Uani d . 1 . . C
    O21A 1.17476(17)  .55117(5)  .71922(9)  .0306(3) Uani d . 1 . . O
    O22A 1.27283(15)  .50093(5)  .59729(9)  .0262(3) Uani d . 1 . . O
    H22A 1.322(4)  .4843(14)  .648(3)  .084(11) Uiso d . 1 . . H
    C3A 1.14044(17)  .62763(6)  .53850(11)  .0157(3) Uani d . 1 . . C
    Cl3A 1.31328(5)  .632293(17)  .46804(3)  .02498(8) Uani d . 1 . . Cl
    C4A 1.14115(18)  .65700(6)  .63701(11)  .0172(3) Uani d . 1 . . C
    Cl4A 1.30844(5)  .674789(18)  .69863(3)  .02864(9) Uani d . 1 . . Cl
    C5A  .99106(18)  .66355(6)  .66446(11)  .0173(3) Uani d . 1 . . C
    Cl5A  .92267(5)  .693265(17)  .76826(3)  .02881(9) Uani d . 1 . . Cl
    C6A  .88620(17)  .63890(6)  .58465(11)  .0162(3) Uani d . 1 . . C
    Cl6A  .68949(5)  .660605(19)  .58116(3)  .02991(9) Uani d . 1 . . Cl
    C7A  .98846(18)  .65370(6)  .49272(11)  .0172(3) Uani d . 1 . . C
    Cl73  .92290(5)  .623165(17)  .38217(3)  .02441(8) Uani d . 1 . . Cl
    Cl74 1.00832(5)  .723432(16)  .47172(3)  .02732(9) Uani d . 1 . . Cl
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C11 . 1.515(2) ?
    C1 C6 . 1.5558(19) ?
    C1 C2 . 1.574(2) ?
    C1 H1 . 1.0000 ?
    C11 O11 . 1.214(2) ?
    C11 O12 . 1.3180(18) ?
    O12 H12 .  .79(3) ?
    C2 C21 . 1.517(2) ?
    C2 C3 . 1.555(2) ?
    C2 H2 . 1.0000 ?
    C21 O21 . 1.2206(19) ?
    C21 O22 . 1.312(2) ?
    O22 H22 .  .76(3) ?
    C3 C4 . 1.526(2) ?
    C3 C7 . 1.566(2) ?
    C3 Cl3 . 1.7506(15) ?
    C4 C5 . 1.334(2) ?
    C4 Cl4 . 1.6959(15) ?
    C5 C6 . 1.531(2) ?
    C5 Cl5 . 1.6944(15) ?
    C6 C7 . 1.564(2) ?
    C6 Cl6 . 1.7524(15) ?
    C7 Cl72 . 1.7612(15) ?
    C7 Cl71 . 1.7717(15) ?
    C1A C11A . 1.512(2) ?
    C1A C6A . 1.554(2) ?
    C1A C2A . 1.571(2) ?
    C1A H1A . 1.0000 ?
    C11A O11A . 1.2171(19) ?
    C11A O12A . 1.3178(19) ?
    O12A H12A .  .83(3) ?
    C2A C21A . 1.522(2) ?
    C2A C3A . 1.567(2) ?
    C2A H2A . 1.0000 ?
    C21A O21A . 1.2205(19) ?
    C21A O22A . 1.3085(19) ?
    O22A H22A .  .90(4) ?
    C3A C4A . 1.524(2) ?
    C3A C7A . 1.562(2) ?
    C3A Cl3A . 1.7547(15) ?
    C4A C5A . 1.333(2) ?
    C4A Cl4A . 1.6958(15) ?
    C5A C6A . 1.524(2) ?
    C5A Cl5A . 1.6967(15) ?
    C6A C7A . 1.567(2) ?
    C6A Cl6A . 1.7463(15) ?
    C7A Cl74 . 1.7615(15) ?
    C7A Cl73 . 1.7686(16) ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C11 C1 C6 . . 114.08(12) ?
    C11 C1 C2 . . 114.67(12) ?
    C6 C1 C2 . . 103.03(11) ?
    C11 C1 H1 . . 108.2 ?
    C6 C1 H1 . . 108.2 ?
    C2 C1 H1 . . 108.2 ?
    O11 C11 O12 . . 124.46(14) ?
    O11 C11 C1 . . 124.17(14) ?
    O12 C11 C1 . . 111.36(13) ?
    C11 O12 H12 . . 110(2) ?
    C21 C2 C3 . . 115.67(13) ?
    C21 C2 C1 . . 115.62(12) ?
    C3 C2 C1 . . 102.10(11) ?
    C21 C2 H2 . . 107.7 ?
    C3 C2 H2 . . 107.7 ?
    C1 C2 H2 . . 107.7 ?
    O21 C21 O22 . . 124.74(14) ?
    O21 C21 C2 . . 124.27(14) ?
    O22 C21 C2 . . 110.97(13) ?
    C21 O22 H22 . . 109(2) ?
    C4 C3 C2 . . 111.05(12) ?
    C4 C3 C7 . . 98.80(11) ?
    C2 C3 C7 . . 99.84(11) ?
    C4 C3 Cl3 . . 115.98(11) ?
    C2 C3 Cl3 . . 112.87(10) ?
    C7 C3 Cl3 . . 116.45(10) ?
    C5 C4 C3 . . 108.03(13) ?
    C5 C4 Cl4 . . 127.72(12) ?
    C3 C4 Cl4 . . 124.14(11) ?
    C4 C5 C6 . . 106.94(12) ?
    C4 C5 Cl5 . . 127.90(12) ?
    C6 C5 Cl5 . . 125.08(11) ?
    C5 C6 C1 . . 109.47(11) ?
    C5 C6 C7 . . 98.40(11) ?
    C1 C6 C7 . . 101.13(11) ?
    C5 C6 Cl6 . . 116.70(10) ?
    C1 C6 Cl6 . . 113.50(10) ?
    C7 C6 Cl6 . . 115.66(10) ?
    C6 C7 C3 . . 92.11(10) ?
    C6 C7 Cl72 . . 112.86(10) ?
    C3 C7 Cl72 . . 114.61(10) ?
    C6 C7 Cl71 . . 115.12(10) ?
    C3 C7 Cl71 . . 113.95(10) ?
    Cl72 C7 Cl71 . . 107.81(8) ?
    C11A C1A C6A . . 116.40(12) ?
    C11A C1A C2A . . 116.03(12) ?
    C6A C1A C2A . . 103.66(11) ?
    C11A C1A H1A . . 106.7 ?
    C6A C1A H1A . . 106.7 ?
    C2A C1A H1A . . 106.7 ?
    O11A C11A O12A . . 124.87(14) ?
    O11A C11A C1A . . 124.50(14) ?
    O12A C11A C1A . . 110.53(13) ?
    C11A O12A H12A . . 111(2) ?
    C21A C2A C3A . . 112.02(12) ?
    C21A C2A C1A . . 113.92(12) ?
    C3A C2A C1A . . 101.76(11) ?
    C21A C2A H2A . . 109.6 ?
    C3A C2A H2A . . 109.6 ?
    C1A C2A H2A . . 109.6 ?
    O21A C21A O22A . . 124.38(14) ?
    O21A C21A C2A . . 121.49(14) ?
    O22A C21A C2A . . 114.12(13) ?
    C21A O22A H22A . . 108(2) ?
    C4A C3A C7A . . 98.66(11) ?
    C4A C3A C2A . . 109.00(12) ?
    C7A C3A C2A . . 101.24(11) ?
    C4A C3A Cl3A . . 116.71(11) ?
    C7A C3A Cl3A . . 116.05(10) ?
    C2A C3A Cl3A . . 113.25(10) ?
    C5A C4A C3A . . 107.81(13) ?
    C5A C4A Cl4A . . 128.31(12) ?
    C3A C4A Cl4A . . 123.83(11) ?
    C4A C5A C6A . . 107.49(13) ?
    C4A C5A Cl5A . . 127.96(12) ?
    C6A C5A Cl5A . . 124.55(11) ?
    C5A C6A C1A . . 109.71(12) ?
    C5A C6A C7A . . 98.81(11) ?
    C1A C6A C7A . . 99.93(11) ?
    C5A C6A Cl6A . . 116.32(11) ?
    C1A C6A Cl6A . . 114.16(10) ?
    C7A C6A Cl6A . . 115.79(10) ?
    C3A C7A C6A . . 92.34(11) ?
    C3A C7A Cl74 . . 113.09(10) ?
    C6A C7A Cl74 . . 114.39(11) ?
    C3A C7A Cl73 . . 114.37(11) ?
    C6A C7A Cl73 . . 113.97(10) ?
    Cl74 C7A Cl73 . . 108.21(8) ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C6 C1 C11 O11 . . . . -3.7(2) ?
    C2 C1 C11 O11 . . . . 114.75(17) ?
    C6 C1 C11 O12 . . . . 176.07(13) ?
    C2 C1 C11 O12 . . . . -65.44(17) ?
    C11 C1 C2 C21 . . . . 6.24(18) ?
    C6 C1 C2 C21 . . . . 130.80(13) ?
    C11 C1 C2 C3 . . . . -120.21(13) ?
    C6 C1 C2 C3 . . . . 4.34(13) ?
    C3 C2 C21 O21 . . . . 49.8(2) ?
    C1 C2 C21 O21 . . . . -69.4(2) ?
    C3 C2 C21 O22 . . . . -131.57(15) ?
    C1 C2 C21 O22 . . . . 109.20(16) ?
    C21 C2 C3 C4 . . . . -64.11(16) ?
    C1 C2 C3 C4 . . . . 62.31(14) ?
    C21 C2 C3 C7 . . . . -167.58(12) ?
    C1 C2 C3 C7 . . . . -41.17(13) ?
    C21 C2 C3 Cl3 . . . . 68.10(15) ?
    C1 C2 C3 Cl3 . . . . -165.49(9) ?
    C2 C3 C4 C5 . . . . -70.34(16) ?
    C7 C3 C4 C5 . . . . 33.83(15) ?
    Cl3 C3 C4 C5 . . . . 159.06(11) ?
    C2 C3 C4 Cl4 . . . . 113.23(13) ?
    C7 C3 C4 Cl4 . . . . -142.60(12) ?
    Cl3 C3 C4 Cl4 . . . . -17.37(18) ?
    C3 C4 C5 C6 . . . . 2.37(16) ?
    Cl4 C4 C5 C6 . . . . 178.63(11) ?
    C3 C4 C5 Cl5 . . . . -174.32(11) ?
    Cl4 C4 C5 Cl5 . . . . 1.9(2) ?
    C4 C5 C6 C1 . . . . 67.31(15) ?
    Cl5 C5 C6 C1 . . . . -115.88(13) ?
    C4 C5 C6 C7 . . . . -37.71(14) ?
    Cl5 C5 C6 C7 . . . . 139.10(11) ?
    C4 C5 C6 Cl6 . . . . -162.06(11) ?
    Cl5 C5 C6 Cl6 . . . . 14.75(17) ?
    C11 C1 C6 C5 . . . . 55.83(16) ?
    C2 C1 C6 C5 . . . . -69.11(14) ?
    C11 C1 C6 C7 . . . . 158.98(12) ?
    C2 C1 C6 C7 . . . . 34.04(13) ?
    C11 C1 C6 Cl6 . . . . -76.50(14) ?
    C2 C1 C6 Cl6 . . . . 158.56(9) ?
    C5 C6 C7 C3 . . . . 54.14(12) ?
    C1 C6 C7 C3 . . . . -57.72(12) ?
    Cl6 C6 C7 C3 . . . . 179.23(10) ?
    C5 C6 C7 Cl72 . . . . -63.75(12) ?
    C1 C6 C7 Cl72 . . . . -175.61(10) ?
    Cl6 C6 C7 Cl72 . . . . 61.34(13) ?
    C5 C6 C7 Cl71 . . . . 171.91(10) ?
    C1 C6 C7 Cl71 . . . . 60.04(13) ?
    Cl6 C6 C7 Cl71 . . . . -63.00(13) ?
    C4 C3 C7 C6 . . . . -52.78(12) ?
    C2 C3 C7 C6 . . . . 60.53(12) ?
    Cl3 C3 C7 C6 . . . . -177.68(10) ?
    C4 C3 C7 Cl72 . . . . 63.60(13) ?
    C2 C3 C7 Cl72 . . . . 176.91(10) ?
    Cl3 C3 C7 Cl72 . . . . -61.30(13) ?
    C4 C3 C7 Cl71 . . . . -171.54(10) ?
    C2 C3 C7 Cl71 . . . . -58.24(13) ?
    Cl3 C3 C7 Cl71 . . . . 63.56(13) ?
    C6A C1A C11A O11A . . . . 6.3(2) ?
    C2A C1A C11A O11A . . . . 128.70(17) ?
    C6A C1A C11A O12A . . . . -177.29(13) ?
    C2A C1A C11A O12A . . . . -54.89(18) ?
    C11A C1A C2A C21A . . . . -9.80(18) ?
    C6A C1A C2A C21A . . . . 119.10(13) ?
    C11A C1A C2A C3A . . . . -130.55(13) ?
    C6A C1A C2A C3A . . . . -1.66(14) ?
    C3A C2A C21A O21A . . . . 70.11(19) ?
    C1A C2A C21A O21A . . . . -44.7(2) ?
    C3A C2A C21A O22A . . . . -110.82(15) ?
    C1A C2A C21A O22A . . . . 134.35(14) ?
    C21A C2A C3A C4A . . . . -54.88(16) ?
    C1A C2A C3A C4A . . . . 67.19(14) ?
    C21A C2A C3A C7A . . . . -158.22(12) ?
    C1A C2A C3A C7A . . . . -36.15(13) ?
    C21A C2A C3A Cl3A . . . . 76.84(14) ?
    C1A C2A C3A Cl3A . . . . -161.09(10) ?
    C7A C3A C4A C5A . . . . 35.68(15) ?
    C2A C3A C4A C5A . . . . -69.45(15) ?
    Cl3A C3A C4A C5A . . . . 160.70(11) ?
    C7A C3A C4A Cl4A . . . . -146.44(11) ?
    C2A C3A C4A Cl4A . . . . 108.43(13) ?
    Cl3A C3A C4A Cl4A . . . . -21.42(17) ?
    C3A C4A C5A C6A . . . .  -.23(16) ?
    Cl4A C4A C5A C6A . . . . -177.99(11) ?
    C3A C4A C5A Cl5A . . . . 179.55(11) ?
    Cl4A C4A C5A Cl5A . . . . 1.8(2) ?
    C4A C5A C6A C1A . . . . 68.74(15) ?
    Cl5A C5A C6A C1A . . . . -111.04(13) ?
    C4A C5A C6A C7A . . . . -35.20(15) ?
    Cl5A C5A C6A C7A . . . . 145.02(11) ?
    C4A C5A C6A Cl6A . . . . -159.79(11) ?
    Cl5A C5A C6A Cl6A . . . . 20.42(17) ?
    C11A C1A C6A C5A . . . . 64.14(16) ?
    C2A C1A C6A C5A . . . . -64.53(14) ?
    C11A C1A C6A C7A . . . . 167.31(12) ?
    C2A C1A C6A C7A . . . . 38.64(13) ?
    C11A C1A C6A Cl6A . . . . -68.46(16) ?
    C2A C1A C6A Cl6A . . . . 162.87(10) ?
    C4A C3A C7A C6A . . . . -52.92(12) ?
    C2A C3A C7A C6A . . . . 58.55(12) ?
    Cl3A C3A C7A C6A . . . . -178.41(10) ?
    C4A C3A C7A Cl74 . . . . 64.90(13) ?
    C2A C3A C7A Cl74 . . . . 176.37(10) ?
    Cl3A C3A C7A Cl74 . . . . -60.59(14) ?
    C4A C3A C7A Cl73 . . . . -170.62(10) ?
    C2A C3A C7A Cl73 . . . . -59.14(13) ?
    Cl3A C3A C7A Cl73 . . . . 63.90(13) ?
    C5A C6A C7A C3A . . . . 52.92(12) ?
    C1A C6A C7A C3A . . . . -59.01(12) ?
    Cl6A C6A C7A C3A . . . . 177.90(10) ?
    C5A C6A C7A Cl74 . . . . -63.79(13) ?
    C1A C6A C7A Cl74 . . . . -175.73(10) ?
    Cl6A C6A C7A Cl74 . . . . 61.18(14) ?
    C5A C6A C7A Cl73 . . . . 170.96(10) ?
    C1A C6A C7A Cl73 . . . . 59.03(13) ?
    Cl6A C6A C7A Cl73 . . . . -64.06(13) ?
loop_
    _geom_hbond_atom_site_label_D
    _geom_hbond_atom_site_label_H
    _geom_hbond_atom_site_label_A
    _geom_hbond_site_symmetry_A
    _geom_hbond_distance_DH
    _geom_hbond_distance_HA
    _geom_hbond_distance_DA
    _geom_hbond_angle_DHA
    O12 H12 O11A 3_666  .79(3) 1.88(3) 2.6627(17) 174(3)
    O22 H22 O21A 3_766  .76(3) 1.86(3) 2.6186(17) 175(3)
    O12A H12A O11 3_666  .83(3) 1.80(3) 2.6320(17) 178(3)
    O22A H22A O21 3_766  .90(4) 1.84(4) 2.7347(17) 171(3)
data_V
_audit_creation_method     SHELXL97
_chemical_name_systematic
;
ethyl
1,2,3,4,7,7-hexachloro-6-carboxybicyclo[2.2.1]hept-2-ene-endo-cis-5-carboxylate
monohydrate
;
_chemical_name_common     ?
_chemical_formula_moiety     'C11 H8 Cl6 O4 , H2 O'
_chemical_formula_sum     'C11 H8 Cl6 O4 , H2 O'
_chemical_formula_weight     434.89
_chemical_melting_point     ?
_symmetry_cell_setting     Triclinic
_symmetry_space_group_name_H-M     P-1
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x, -y, -z'
_cell_length_a     8.616(3)
_cell_length_b     9.281(2)
_cell_length_c     10.460(4)
_cell_angle_alpha     100.53(2)
_cell_angle_beta     94.00(2)
_cell_angle_gamma     95.06(2)
_cell_volume     816.0(5)
_cell_formula_units_Z     2
_cell_measurement_reflns_used     2320
_cell_measurement_theta_min     1
_cell_measurement_theta_max     20
_cell_measurement_temperature     173(2)
_exptl_crystal_description     plate
_exptl_crystal_colour     colourless
_exptl_crystal_size_max      .25
_exptl_crystal_size_mid      .20
_exptl_crystal_size_min      .10
_exptl_crystal_density_diffrn     1.770
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     436
_exptl_absorpt_coefficient_mu     1.069
_exptl_absorpt_correction_type     empirical
_exptl_absorpt_process_details     '(SADABS; Sheldrick, 1996)'
_exptl_absorpt_correction_T_min      .776
_exptl_absorpt_correction_T_max      .901
_exptl_special_details
;
;
_diffrn_ambient_temperature     173(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength      .71073
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Siemens CCD three-circle'
_diffrn_measurement_method     ω
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     11168
_diffrn_reflns_av_R_equivalents      .086
_diffrn_reflns_av_sigmaI/netI      .104
_diffrn_reflns_theta_min     1.99
_diffrn_reflns_theta_max     25.03
_diffrn_reflns_theta_full     25.03
_diffrn_measured_fraction_theta_max     1.000
_diffrn_measured_fraction_theta_full     1.000
_diffrn_reflns_limit_h_min     -10
_diffrn_reflns_limit_h_max     10
_diffrn_reflns_limit_k_min     -11
_diffrn_reflns_limit_k_max     11
_diffrn_reflns_limit_l_min     -12
_diffrn_reflns_limit_l_max     12
_diffrn_standards_number     69
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     900
_diffrn_standards_decay_%     0
_refine_special_details
;
 Refinement of F² against ALL reflections.  The weighted R-factor wR and
 goodness of fit S are based on F², conventional R-factors R are based
 on F, with F set to zero for negative F². The threshold expression of
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is
 not relevant to the choice of reflections for refinement.  R-factors based
 on F² are statistically about twice as large as those based on F, and R-
 factors based on ALL data will be even larger.
;
_reflns_number_total     2886
_reflns_number_gt     1709
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all      .123
_refine_ls_R_factor_gt      .056
_refine_ls_wR_factor_ref      .136
_refine_ls_goodness_of_fit_ref     1.003
_refine_ls_restrained_S_all     1.003
_refine_ls_number_reflns     2886
_refine_ls_number_parameters     211
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     mixed
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
               'calc w = 1/[σ²(Fo²)+(0.0636P)²] where P=(Fo²+2Fc²)/3'
_refine_ls_shift/su_max      .003
_refine_ls_shift/su_mean      .000
_refine_diff_density_max      .47
_refine_diff_density_min      -.45
_refine_ls_extinction_method     none
_refine_ls_extinction_coef     ?
loop_
    _atom_type_symbol
    _atom_type_description
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    _atom_type_scat_source
    'C' 'C'  .0033  .0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H'  .0000  .0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O'  .0106  .0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Cl' 'Cl'  .1484  .1585
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Siemens, 1995)'
_computing_cell_refinement     'SMART'
_computing_data_reduction     'SAINT (Siemens, 1995)'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1990)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'XP in SHELXTL-Plus (Sheldrick, 1991)'
_computing_publication_material     ?
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    _atom_site_adp_type
    _atom_site_calc_flag
    _atom_site_refinement_flags
    _atom_site_occupancy
    _atom_site_disorder_assembly
    _atom_site_disorder_group
    _atom_site_type_symbol
    C1  .7769(6)  .6312(5)  .6060(5)  .0200(12) Uani d . 1 . . C
    H1  .7816  .5234  .5745  .024 Uiso calc R 1 . . H
    C11  .8086(6)  .7067(6)  .4925(5)  .0226(13) Uani d . 1 . . C
    O11  .9144(4)  .8017(4)  .4920(4)  .0329(10) Uani d . 1 . . O
    O12  .7029(4)  .6499(4)  .3930(3)  .0247(9) Uani d . 1 . . O
    C12  .7169(7)  .7031(6)  .2712(6)  .0393(16) Uani d . 1 . . C
    H12A  .6750  .6237  .1970  .047 Uiso calc R 1 . . H
    H12B  .8287  .7289  .2610  .047 Uiso calc R 1 . . H
    C13  .6282(6)  .8380(6)  .2681(6)  .0333(15) Uani d . 1 . . C
    H13A  .6398  .8710  .1852  .050 Uiso calc R 1 . . H
    H13B  .6707  .9173  .3405  .050 Uiso calc R 1 . . H
    H13C  .5171  .8122  .2766  .050 Uiso calc R 1 . . H
    C2  .6151(6)  .6492(5)  .6608(5)  .0195(12) Uani d . 1 . . C
    H2  .5517  .5511  .6465  .023 Uiso calc R 1 . . H
    C21  .5231(6)  .7582(6)  .6025(5)  .0217(13) Uani d . 1 . . C
    O21  .5761(4)  .8813(4)  .5974(4)  .0286(9) Uani d . 1 . . O
    O22  .3798(4)  .7006(4)  .5563(4)  .0297(10) Uani d . 1 . . O
    H22  .321(8)  .765(7)  .514(7)  .07(2) Uiso d . 1 . . H
    C3  .6633(6)  .7046(6)  .8105(5)  .0238(13) Uani d . 1 . . C
    Cl3  .50826(17)  .68412(17)  .90810(14)  .0354(4) Uani d . 1 . . Cl
    C4  .7522(6)  .8567(6)  .8313(5)  .0231(13) Uani d . 1 . . C
    Cl4  .68432(18) 1.01342(15)  .90645(15)  .0387(4) Uani d . 1 . . Cl
    C5  .8900(6)  .8423(6)  .7829(5)  .0250(13) Uani d . 1 . . C
    Cl5 1.03712(18)  .97470(16)  .78113(16)  .0413(4) Uani d . 1 . . Cl
    C6  .8944(6)  .6787(6)  .7277(5)  .0226(13) Uani d . 1 . . C
    Cl6 1.08154(16)  .62094(17)  .70714(15)  .0377(4) Uani d . 1 . . Cl
    C7  .8036(6)  .6148(6)  .8307(5)  .0255(13) Uani d . 1 . . C
    Cl71  .89901(17)  .66000(16)  .98949(14)  .0346(4) Uani d . 1 . . Cl
    Cl72  .75705(18)  .42083(15)  .79200(15)  .0351(4) Uani d . 1 . . Cl
    O1W 1.2286(6)  .8679(5)  .4347(5)  .0345(11) Uani d . 1 . . O
    H1W 1.125(8)  .884(7)  .452(7)  .07(3) Uiso d . 1 . . H
    H2W 1.267(7)  .941(7)  .431(6)  .04(2) Uiso d . 1 . . H
_geom_special_details
;
 All esds (except the esd in the dihedral angle between two l.s. planes)
 are estimated using the full covariance matrix.  The cell esds are taken
 into account individually in the estimation of esds in distances, angles
 and torsion angles; correlations between esds in cell parameters are only
 used when they are defined by crystal symmetry.  An approximate (isotropic)
 treatment of cell esds is used for estimating esds involving l.s. planes.
;
loop_
    _geom_bond_atom_site_label_1
    _geom_bond_atom_site_label_2
    _geom_bond_site_symmetry_2
    _geom_bond_distance
    _geom_bond_publ_flag
    C1 C11 . 1.513(7) ?
    C1 C6 . 1.542(7) ?
    C1 C2 . 1.555(7) ?
    C1 H1 . 1.0000 ?
    C11 O11 . 1.212(6) ?
    C11 O12 . 1.332(6) ?
    O12 C12 . 1.457(6) ?
    C12 C13 . 1.528(8) ?
    C12 H12A .  .9900 ?
    C12 H12B .  .9900 ?
    C13 H13A .  .9800 ?
    C13 H13B .  .9800 ?
    C13 H13C .  .9800 ?
    C2 C21 . 1.524(7) ?
    C2 C3 . 1.571(7) ?
    C2 H2 . 1.0000 ?
    C21 O21 . 1.204(6) ?
    C21 O22 . 1.323(6) ?
    O22 H22 .  .96(7) ?
    C3 C4 . 1.517(7) ?
    C3 C7 . 1.551(7) ?
    C3 Cl3 . 1.754(5) ?
    C4 C5 . 1.331(7) ?
    C4 Cl4 . 1.695(5) ?
    C5 C6 . 1.528(7) ?
    C5 Cl5 . 1.689(5) ?
    C6 C7 . 1.547(7) ?
    C6 Cl6 . 1.758(5) ?
    C7 Cl71 . 1.762(5) ?
    C7 Cl72 . 1.775(5) ?
    O1W H1W .  .94(7) ?
    O1W H2W .  .74(6) ?
loop_
    _geom_angle_atom_site_label_1
    _geom_angle_atom_site_label_2
    _geom_angle_atom_site_label_3
    _geom_angle_site_symmetry_1
    _geom_angle_site_symmetry_3
    _geom_angle
    _geom_angle_publ_flag
    C11 C1 C6 . . 115.6(4) ?
    C11 C1 C2 . . 115.9(4) ?
    C6 C1 C2 . . 103.8(4) ?
    C11 C1 H1 . . 107.0 ?
    C6 C1 H1 . . 107.0 ?
    C2 C1 H1 . . 107.0 ?
    O11 C11 O12 . . 125.8(5) ?
    O11 C11 C1 . . 125.4(5) ?
    O12 C11 C1 . . 108.8(4) ?
    C11 O12 C12 . . 117.7(4) ?
    O12 C12 C13 . . 111.5(5) ?
    O12 C12 H12A . . 109.3 ?
    C13 C12 H12A . . 109.3 ?
    O12 C12 H12B . . 109.3 ?
    C13 C12 H12B . . 109.3 ?
    H12A C12 H12B . . 108.0 ?
    C12 C13 H13A . . 109.5 ?
    C12 C13 H13B . . 109.5 ?
    H13A C13 H13B . . 109.5 ?
    C12 C13 H13C . . 109.5 ?
    H13A C13 H13C . . 109.5 ?
    H13B C13 H13C . . 109.5 ?
    C21 C2 C1 . . 113.5(4) ?
    C21 C2 C3 . . 111.9(4) ?
    C1 C2 C3 . . 101.7(4) ?
    C21 C2 H2 . . 109.8 ?
    C1 C2 H2 . . 109.8 ?
    C3 C2 H2 . . 109.8 ?
    O21 C21 O22 . . 124.3(5) ?
    O21 C21 C2 . . 123.7(5) ?
    O22 C21 C2 . . 112.0(4) ?
    C21 O22 H22 . . 114(4) ?
    C4 C3 C7 . . 98.5(4) ?
    C4 C3 C2 . . 109.2(4) ?
    C7 C3 C2 . . 100.9(4) ?
    C4 C3 Cl3 . . 116.4(4) ?
    C7 C3 Cl3 . . 116.7(4) ?
    C2 C3 Cl3 . . 113.3(4) ?
    C5 C4 C3 . . 107.8(4) ?
    C5 C4 Cl4 . . 127.7(4) ?
    C3 C4 Cl4 . . 124.5(4) ?
    C4 C5 C6 . . 107.0(5) ?
    C4 C5 Cl5 . . 128.4(4) ?
    C6 C5 Cl5 . . 124.6(4) ?
    C5 C6 C1 . . 109.7(4) ?
    C5 C6 C7 . . 98.5(4) ?
    C1 C6 C7 . . 100.8(4) ?
    C5 C6 Cl6 . . 115.7(4) ?
    C1 C6 Cl6 . . 114.5(4) ?
    C7 C6 Cl6 . . 115.7(4) ?
    C6 C7 C3 . . 92.7(4) ?
    C6 C7 Cl71 . . 113.7(4) ?
    C3 C7 Cl71 . . 113.6(4) ?
    C6 C7 Cl72 . . 114.0(4) ?
    C3 C7 Cl72 . . 114.5(4) ?
    Cl71 C7 Cl72 . . 107.9(3) ?
    H1W O1W H2W . . 105(6) ?
loop_
    _geom_torsion_atom_site_label_1
    _geom_torsion_atom_site_label_2
    _geom_torsion_atom_site_label_3
    _geom_torsion_atom_site_label_4
    _geom_torsion_site_symmetry_1
    _geom_torsion_site_symmetry_2
    _geom_torsion_site_symmetry_3
    _geom_torsion_site_symmetry_4
    _geom_torsion
    _geom_torsion_publ_flag
    C6 C1 C11 O11 . . . . -2.0(7) ?
    C2 C1 C11 O11 . . . . 119.7(6) ?
    C6 C1 C11 O12 . . . . 177.0(4) ?
    C2 C1 C11 O12 . . . . -61.3(5) ?
    O11 C11 O12 C12 . . . . 1.6(7) ?
    C1 C11 O12 C12 . . . . -177.3(4) ?
    C11 O12 C12 C13 . . . . -88.8(6) ?
    C11 C1 C2 C21 . . . . -7.9(6) ?
    C6 C1 C2 C21 . . . . 119.9(4) ?
    C11 C1 C2 C3 . . . . -128.3(4) ?
    C6 C1 C2 C3 . . . .  -.5(5) ?
    C1 C2 C21 O21 . . . . -50.9(7) ?
    C3 C2 C21 O21 . . . . 63.5(6) ?
    C1 C2 C21 O22 . . . . 127.9(5) ?
    C3 C2 C21 O22 . . . . -117.8(5) ?
    C21 C2 C3 C4 . . . . -54.9(5) ?
    C1 C2 C3 C4 . . . . 66.5(5) ?
    C21 C2 C3 C7 . . . . -158.0(4) ?
    C1 C2 C3 C7 . . . . -36.6(5) ?
    C21 C2 C3 Cl3 . . . . 76.5(5) ?
    C1 C2 C3 Cl3 . . . . -162.1(3) ?
    C7 C3 C4 C5 . . . . 35.2(5) ?
    C2 C3 C4 C5 . . . . -69.5(5) ?
    Cl3 C3 C4 C5 . . . . 160.8(4) ?
    C7 C3 C4 Cl4 . . . . -143.6(4) ?
    C2 C3 C4 Cl4 . . . . 111.7(5) ?
    Cl3 C3 C4 Cl4 . . . . -18.1(6) ?
    C3 C4 C5 C6 . . . .  .4(6) ?
    Cl4 C4 C5 C6 . . . . 179.1(4) ?
    C3 C4 C5 Cl5 . . . . -179.0(4) ?
    Cl4 C4 C5 Cl5 . . . .  -.3(8) ?
    C4 C5 C6 C1 . . . . 68.8(5) ?
    Cl5 C5 C6 C1 . . . . -111.8(5) ?
    C4 C5 C6 C7 . . . . -35.9(5) ?
    Cl5 C5 C6 C7 . . . . 143.5(4) ?
    C4 C5 C6 Cl6 . . . . -159.9(4) ?
    Cl5 C5 C6 Cl6 . . . . 19.5(6) ?
    C11 C1 C6 C5 . . . . 62.3(5) ?
    C2 C1 C6 C5 . . . . -65.7(5) ?
    C11 C1 C6 C7 . . . . 165.5(4) ?
    C2 C1 C6 C7 . . . . 37.5(5) ?
    C11 C1 C6 Cl6 . . . . -69.7(5) ?
    C2 C1 C6 Cl6 . . . . 162.3(3) ?
    C5 C6 C7 C3 . . . . 53.6(4) ?
    C1 C6 C7 C3 . . . . -58.4(4) ?
    Cl6 C6 C7 C3 . . . . 177.6(4) ?
    C5 C6 C7 Cl71 . . . . -63.7(4) ?
    C1 C6 C7 Cl71 . . . . -175.7(3) ?
    Cl6 C6 C7 Cl71 . . . . 60.3(5) ?
    C5 C6 C7 Cl72 . . . . 172.0(3) ?
    C1 C6 C7 Cl72 . . . . 60.0(4) ?
    Cl6 C6 C7 Cl72 . . . . -64.1(5) ?
    C4 C3 C7 C6 . . . . -53.4(4) ?
    C2 C3 C7 C6 . . . . 58.1(4) ?
    Cl3 C3 C7 C6 . . . . -178.7(4) ?
    C4 C3 C7 Cl71 . . . . 63.9(5) ?
    C2 C3 C7 Cl71 . . . . 175.5(3) ?
    Cl3 C3 C7 Cl71 . . . . -61.4(5) ?
    C4 C3 C7 Cl72 . . . . -171.4(4) ?
    C2 C3 C7 Cl72 . . . . -59.9(5) ?
    Cl3 C3 C7 Cl72 . . . . 63.3(5) ?
loop_
    _geom_hbond_atom_site_label_D
    _geom_hbond_atom_site_label_H
    _geom_hbond_atom_site_label_A
    _geom_hbond_site_symmetry_A
    _geom_hbond_distance_DH
    _geom_hbond_distance_HA
    _geom_hbond_distance_DA
    _geom_hbond_angle_DHA
    O22 H22 O1W 1_455  .96(7) 1.60(7) 2.564(6) 176(6)
    O1W H1W O11 .  .94(7) 2.01(7) 2.852(6) 148(6)
    O1W H2W O21 2_776  .74(6) 2.12(6) 2.835(6) 165(7)
data_global
_journal_date_recd_electronic     2000-07-11
_journal_date_accepted     2000-07-19
_journal_name_full     'Acta Crystallographica, Section C'
_journal_year     2000
_journal_volume     56
_journal_issue     11
_journal_page_first     1338
_journal_page_last     1342
_journal_paper_category     FO
_publ_contact_author_name     'Dr Michael Bolte'
_publ_contact_author_address
;
      Institut fur Organische Chemie
      J. W. Goethe-Universitat
      Marie-Curie-Strasse 11
      60439 Frankfurt/Main
      Germany
;
_publ_contact_author_email     bolte@chemie.uni-frankfurt.de
_publ_contact_author_fax     '49 69 798 29128'
_publ_contact_author_phone     '49 69 798 29136'
_publ_section_title
;
Diels-Alder adducts of maleic anhydride and dienes:
new compounds by crystallization
;
loop_
    _publ_author_name
    _publ_author_address
    'Bolte, Michael'
;
Institut für Organische Chemie
Goethe-Universität Frankfurt
Marie-Curie-Strasse 11
60439 Frankfurt/Main
Germany
;
    'Degen, Alexander'
;
Institut für Organische Chemie
Goethe-Universität Frankfurt
Marie-Curie-Strasse 11
60439 Frankfurt/Main
Germany
;
    'Egert, Ernst'
;
Institut für Organische Chemie
Goethe-Universität Frankfurt
Marie-Curie-Strasse 11
60439 Frankfurt/Main
Germany
;
_exptl_special_details
;
The data collection nominally covered a sphere of reciprocal
space, by a combination of eight, for (I) and (IVa), seven, for
(II), (III) and (IVb), and six, for (V), sets of exposures; each set had a
different φ angle for the crystal and each exposure covered 0.3° in ω.
The crystal-to-detector distance was 4 cm for (I) and (IVa), and 4.5 cm for
(II), (III), (IVb) and (V). Coverage of the unique set for all structures
is 100% complete to at least 25.0° in θ. Crystal decay was
monitored by repeating the initial frames at the end of data collection and
analyzing the duplicate reflections.
;
