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###           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 2.1.    #
#                                                                            #
# 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     SHELXL-97
_chemical_name_systematic
;
bis(μ-dimethylphenylsilanolato-κ²O:O)bis[bromido(diethyl
ether)magnesium(II)]
;
_chemical_name_common     ?
_chemical_formula_moiety     'C24 H42 Br2 Mg2 O4 Si2'
_chemical_formula_sum     'C24 H42 Br2 Mg2 O4 Si2'
_chemical_formula_iupac     '[Mg2 Br2 (C8 H11 O1 Si1)2 (C4 H10 O1)2]'
_chemical_formula_weight     659.18
_chemical_melting_point     ?
_symmetry_cell_setting     monoclinic
_symmetry_space_group_name_H-M     'P 21/n'
_symmetry_space_group_name_Hall     '-P 2yn'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x+1/2, y+1/2, -z+1/2'
    '-x, -y, -z'
    'x-1/2, -y-1/2, z-1/2'
_cell_length_a     10.5525(18)
_cell_length_b     11.4674(17)
_cell_length_c     13.412(2)
_cell_angle_alpha     90.00
_cell_angle_beta     91.77(5)
_cell_angle_gamma     90.00
_cell_volume     1622.3(4)
_cell_formula_units_Z     2
_cell_measurement_reflns_used     2891
_cell_measurement_theta_min     3.00
_cell_measurement_theta_max     26.00
_cell_measurement_temperature     100(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colourless
_exptl_crystal_size_max     0.3
_exptl_crystal_size_mid     0.2
_exptl_crystal_size_min     0.1
_exptl_crystal_density_diffrn     1.350
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     680
_exptl_absorpt_coefficient_mu     2.636
_exptl_absorpt_correction_type     multi-scan
_exptl_absorpt_process_details     '(CrystalClear; Rigaku, 2000)'
_exptl_absorpt_correction_T_min     0.4401
_exptl_absorpt_correction_T_max     0.7670
_exptl_special_details
;
;
_diffrn_ambient_temperature     100(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Rigaku R-AXIS IIC image-plate system'
_diffrn_measurement_method     φ
_diffrn_detector_area_resol_mean     105
_diffrn_reflns_number     10801
_diffrn_reflns_av_R_equivalents     0.0398
_diffrn_reflns_av_sigmaI/netI     0.0322
_diffrn_reflns_theta_min     3.00
_diffrn_reflns_theta_max     26.00
_diffrn_reflns_theta_full     26.00
_diffrn_measured_fraction_theta_max     0.907
_diffrn_measured_fraction_theta_full     0.907
_diffrn_reflns_limit_h_min     -11
_diffrn_reflns_limit_h_max     11
_diffrn_reflns_limit_k_min     0
_diffrn_reflns_limit_k_max     14
_diffrn_reflns_limit_l_min     0
_diffrn_reflns_limit_l_max     16
_diffrn_standards_number     0
_diffrn_standards_interval_count     0
_diffrn_standards_interval_time     0
_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     2891
_reflns_number_gt     2652
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all     0.0271
_refine_ls_R_factor_gt     0.0237
_refine_ls_wR_factor_gt     0.0598
_refine_ls_wR_factor_ref     0.0606
_refine_ls_goodness_of_fit_ref     1.060
_refine_ls_restrained_S_all     1.060
_refine_ls_number_reflns     2586
_refine_ls_number_parameters     158
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     constr
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
         'calc w=1/[σ²(Fo²)+(0.0310P)²+0.4905P] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_hydrogens     geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary     difmap
_refine_ls_shift/su_max     0.001
_refine_ls_shift/su_mean     0.000
_refine_diff_density_max     0.317
_refine_diff_density_min     -0.379
_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' 0.0033 0.0016
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'H' 'H' 0.0000 0.0000
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'O' 'O' 0.0106 0.0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Mg' 'Mg' 0.0486 0.0363
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Br' 'Br' -0.2901 2.4595
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Si' 'Si' 0.0817 0.0704
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'CrystalClear (Rigaku, 2000)'
_computing_cell_refinement     'CrystalClear (Rigaku, 2000)'
_computing_data_reduction     'CrystalClear (Rigaku, 2000)'
_computing_structure_solution     'SIR92 (Altomare et al.,  1993)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics
                              'ORTEP-3 (Farrugia, 1997) and PLATON (Spek, 2003)'
_computing_publication_material     'SHELXL97 (Sheldrick, 1997)'
loop_
    _atom_site_type_symbol
    _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
    C C1 0.8552(2) 0.5329(2) 0.23907(17) 0.0315(5) Uani d . 1 . .
    H H1A 0.8071 0.4628 0.2278 0.047 Uiso calc R 1 . .
    H H1B 0.9431 0.5178 0.2278 0.047 Uiso calc R 1 . .
    H H1C 0.8250 0.5925 0.1941 0.047 Uiso calc R 1 . .
    C C2 0.84032(18) 0.57282(19) 0.34462(16) 0.0242(4) Uani d . 1 . .
    H H2A 0.8760 0.5148 0.3900 0.029 Uiso calc R 1 . .
    H H2B 0.8865 0.6451 0.3553 0.029 Uiso calc R 1 . .
    C C3 0.6641(2) 0.70593(16) 0.33316(16) 0.0209(4) Uani d . 1 . .
    H H3A 0.6903 0.7198 0.2655 0.025 Uiso calc R 1 . .
    H H3B 0.7029 0.7650 0.3759 0.025 Uiso calc R 1 . .
    C C4 0.5223(2) 0.71465(19) 0.33709(19) 0.0306(5) Uani d . 1 . .
    H H4A 0.4841 0.6568 0.2941 0.046 Uiso calc R 1 . .
    H H4B 0.4956 0.7908 0.3155 0.046 Uiso calc R 1 . .
    H H4C 0.4966 0.7019 0.4043 0.046 Uiso calc R 1 . .
    C C5 0.4484(2) 0.3444(2) 0.23344(16) 0.0281(5) Uani d . 1 . .
    H H5A 0.4804 0.4145 0.2043 0.042 Uiso calc R 1 . .
    H H5B 0.3988 0.3021 0.1843 0.042 Uiso calc R 1 . .
    H H5C 0.5181 0.2968 0.2568 0.042 Uiso calc R 1 . .
    C C6 0.2125(2) 0.47720(19) 0.29848(17) 0.0282(5) Uani d . 1 . .
    H H6A 0.1624 0.4963 0.3547 0.042 Uiso calc R 1 . .
    H H6B 0.1610 0.4366 0.2495 0.042 Uiso calc R 1 . .
    H H6C 0.2447 0.5475 0.2698 0.042 Uiso calc R 1 . .
    C C7 0.28431(18) 0.24548(17) 0.39752(13) 0.0171(4) Uani d . 1 . .
    C C8 0.1570(2) 0.2311(2) 0.41986(17) 0.0291(5) Uani d . 1 . .
    H H8 0.0994 0.2899 0.4031 0.035 Uiso calc R 1 . .
    C C9 0.1143(2) 0.1310(3) 0.4666(2) 0.0441(7) Uani d . 1 . .
    H H9 0.0294 0.1241 0.4821 0.053 Uiso calc R 1 . .
    C C10 0.1982(2) 0.0413(2) 0.49003(19) 0.0405(6) Uani d . 1 . .
    H H10 0.1693 -0.0264 0.5201 0.049 Uiso calc R 1 . .
    C C11 0.3243(2) 0.05243(19) 0.46889(16) 0.0296(5) Uani d . 1 . .
    H H11 0.3808 -0.0075 0.4847 0.036 Uiso calc R 1 . .
    C C12 0.3672(2) 0.15375(18) 0.42378(15) 0.0215(4) Uani d . 1 . .
    H H12 0.4529 0.1610 0.4107 0.026 Uiso calc R 1 . .
    O O1 0.43354(11) 0.45082(11) 0.42491(9) 0.0124(3) Uani d . 1 . .
    O O2 0.70667(12) 0.59091(11) 0.36570(10) 0.0175(3) Uani d . 1 . .
    Mg Mg1 0.61439(5) 0.47477(5) 0.45034(4) 0.01175(14) Uani d . 1 . .
    Br Br1 0.747945(17) 0.299339(16) 0.452873(14) 0.02127(9) Uani d . 1 . .
    Si Si1 0.34747(5) 0.38250(4) 0.34004(4) 0.01438(13) Uani d . 1 . .
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 0.0311(12) 0.0285(12) 0.0357(13) 0.0070(9) 0.0157(9) 0.0050(10)
    C2 0.0159(10) 0.0238(11) 0.0331(12) -0.0037(7) 0.0045(8) 0.0088(9)
    C3 0.0306(11) 0.0118(9) 0.0209(10) 0.0007(7) 0.0080(8) 0.0040(8)
    C4 0.0303(13) 0.0205(11) 0.0411(14) 0.0039(8) 0.0004(9) 0.0112(10)
    C5 0.0388(12) 0.0292(12) 0.0167(10) -0.0063(9) 0.0048(8) -0.0040(9)
    C6 0.0289(12) 0.0245(11) 0.0303(12) -0.0005(8) -0.0126(9) 0.0028(9)
    C7 0.0239(10) 0.0154(10) 0.0118(9) -0.0056(7) -0.0028(7) -0.0027(7)
    C8 0.0217(11) 0.0354(13) 0.0295(12) -0.0068(9) -0.0077(8) 0.0075(10)
    C9 0.0261(13) 0.0583(18) 0.0473(16) -0.0274(11) -0.0079(10) 0.0175(13)
    C10 0.0515(16) 0.0322(13) 0.0369(14) -0.0275(11) -0.0144(11) 0.0149(11)
    C11 0.0469(14) 0.0172(11) 0.0242(12) -0.0048(9) -0.0067(9) 0.0002(9)
    C12 0.0296(11) 0.0174(10) 0.0177(10) -0.0029(8) 0.0009(8) -0.0036(8)
    O1 0.0139(6) 0.0124(6) 0.0109(6) -0.0019(5) 0.0004(4) 0.0003(5)
    O2 0.0206(7) 0.0134(7) 0.0187(7) 0.0006(5) 0.0069(5) 0.0051(5)
    Mg1 0.0135(3) 0.0101(3) 0.0118(3) -0.0005(2) 0.0020(2) 0.0003(2)
    Br1 0.02410(14) 0.01449(13) 0.02541(14) 0.00631(7) 0.00391(8) 0.00099(8)
    Si1 0.0185(3) 0.0132(3) 0.0113(3) -0.00238(18) -0.00226(18) -0.00013(19)
_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 C2 . 1.501(3) ?
    C1 H1A . 0.9600 ?
    C1 H1B . 0.9600 ?
    C1 H1C . 0.9600 ?
    C2 O2 . 1.462(2) ?
    C2 H2A . 0.9700 ?
    C2 H2B . 0.9700 ?
    C3 O2 . 1.456(2) ?
    C3 C4 . 1.502(3) ?
    C3 H3A . 0.9700 ?
    C3 H3B . 0.9700 ?
    C4 H4A . 0.9600 ?
    C4 H4B . 0.9600 ?
    C4 H4C . 0.9600 ?
    C5 Si1 . 1.861(2) ?
    C5 H5A . 0.9600 ?
    C5 H5B . 0.9600 ?
    C5 H5C . 0.9600 ?
    C6 Si1 . 1.862(2) ?
    C6 H6A . 0.9600 ?
    C6 H6B . 0.9600 ?
    C6 H6C . 0.9600 ?
    C7 C8 . 1.395(3) ?
    C7 C12 . 1.406(3) ?
    C7 Si1 . 1.881(2) ?
    C8 C9 . 1.390(3) ?
    C8 H8 . 0.9300 ?
    C9 C10 . 1.387(4) ?
    C9 H9 . 0.9300 ?
    C10 C11 . 1.375(4) ?
    C10 H10 . 0.9300 ?
    C11 C12 . 1.392(3) ?
    C11 H11 . 0.9300 ?
    C12 H12 . 0.9300 ?
    O1 Si1 . 1.6342(12) ?
    O1 Mg1 . 1.9478(13) ?
    O2 Mg1 . 2.0197(14) ?
    Mg1 O1 3_666 1.9585(13) ?
    Mg1 Br1 . 2.4559(7) ?
    Mg1 Mg1 3_666 2.8526(12) ?
    Mg1 Si1 3_666 3.2673(8) ?
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
    C2 C1 H1A . . 109.5 ?
    C2 C1 H1B . . 109.5 ?
    H1A C1 H1B . . 109.5 ?
    C2 C1 H1C . . 109.5 ?
    H1A C1 H1C . . 109.5 ?
    H1B C1 H1C . . 109.5 ?
    O2 C2 C1 . . 110.83(17) ?
    O2 C2 H2A . . 109.5 ?
    C1 C2 H2A . . 109.5 ?
    O2 C2 H2B . . 109.5 ?
    C1 C2 H2B . . 109.5 ?
    H2A C2 H2B . . 108.1 ?
    O2 C3 C4 . . 110.38(16) ?
    O2 C3 H3A . . 109.6 ?
    C4 C3 H3A . . 109.6 ?
    O2 C3 H3B . . 109.6 ?
    C4 C3 H3B . . 109.6 ?
    H3A C3 H3B . . 108.1 ?
    C3 C4 H4A . . 109.5 ?
    C3 C4 H4B . . 109.5 ?
    H4A C4 H4B . . 109.5 ?
    C3 C4 H4C . . 109.5 ?
    H4A C4 H4C . . 109.5 ?
    H4B C4 H4C . . 109.5 ?
    Si1 C5 H5A . . 109.5 ?
    Si1 C5 H5B . . 109.5 ?
    H5A C5 H5B . . 109.5 ?
    Si1 C5 H5C . . 109.5 ?
    H5A C5 H5C . . 109.5 ?
    H5B C5 H5C . . 109.5 ?
    Si1 C6 H6A . . 109.5 ?
    Si1 C6 H6B . . 109.5 ?
    H6A C6 H6B . . 109.5 ?
    Si1 C6 H6C . . 109.5 ?
    H6A C6 H6C . . 109.5 ?
    H6B C6 H6C . . 109.5 ?
    C8 C7 C12 . . 116.98(19) ?
    C8 C7 Si1 . . 122.84(16) ?
    C12 C7 Si1 . . 120.13(15) ?
    C7 C8 C9 . . 121.5(2) ?
    C7 C8 H8 . . 119.3 ?
    C9 C8 H8 . . 119.3 ?
    C10 C9 C8 . . 120.1(2) ?
    C10 C9 H9 . . 120.0 ?
    C8 C9 H9 . . 120.0 ?
    C11 C10 C9 . . 120.0(2) ?
    C11 C10 H10 . . 120.0 ?
    C9 C10 H10 . . 120.0 ?
    C10 C11 C12 . . 119.8(2) ?
    C10 C11 H11 . . 120.1 ?
    C12 C11 H11 . . 120.1 ?
    C11 C12 C7 . . 121.7(2) ?
    C11 C12 H12 . . 119.2 ?
    C7 C12 H12 . . 119.2 ?
    Si1 O1 Mg1 . . 135.24(8) ?
    Si1 O1 Mg1 . 3_666 130.64(7) ?
    Mg1 O1 Mg1 . 3_666 93.81(5) ?
    C3 O2 C2 . . 111.17(14) ?
    C3 O2 Mg1 . . 128.04(12) ?
    C2 O2 Mg1 . . 120.00(11) ?
    O1 Mg1 O1 . 3_666 86.19(5) ?
    O1 Mg1 O2 . . 118.78(6) ?
    O1 Mg1 O2 3_666 . 109.55(6) ?
    O1 Mg1 Br1 . . 116.46(5) ?
    O1 Mg1 Br1 3_666 . 120.55(4) ?
    O2 Mg1 Br1 . . 105.16(4) ?
    O1 Mg1 Mg1 . 3_666 43.24(4) ?
    O1 Mg1 Mg1 3_666 3_666 42.95(4) ?
    O2 Mg1 Mg1 . 3_666 123.95(5) ?
    Br1 Mg1 Mg1 . 3_666 130.79(3) ?
    O1 Mg1 Si1 . 3_666 108.38(4) ?
    O2 Mg1 Si1 . 3_666 96.00(4) ?
    Br1 Mg1 Si1 . 3_666 110.07(2) ?
    Mg1 Mg1 Si1 3_666 3_666 65.17(2) ?
    O1 Si1 C5 . . 109.19(8) ?
    O1 Si1 C6 . . 109.41(8) ?
    C5 Si1 C6 . . 110.95(11) ?
    O1 Si1 C7 . . 108.14(7) ?
    C5 Si1 C7 . . 109.69(10) ?
    C6 Si1 C7 . . 109.42(10) ?
    C5 Si1 Mg1 . 3_666 136.09(7) ?
    C6 Si1 Mg1 . 3_666 92.19(7) ?
    C7 Si1 Mg1 . 3_666 95.83(6) ?
data_global
_journal_date_recd_electronic     2007-10-13
_journal_date_accepted     2007-11-11
_journal_name_full     'Acta Crystallographica, Section C'
_journal_year     2008
_journal_volume     64
_journal_issue      1
_journal_page_first     m8
_journal_page_last     m9
_journal_paper_category     FM
_journal_coeditor_code     DN3070
_publ_contact_author_name     'Anders Lennartson'
_publ_contact_author_address
;Department of Chemistry,
Göteborg University,
SE-412-96 Göteborg,
Sweden
;
_publ_contact_author_email     anle@chem.gu.se
_publ_contact_author_fax     '+46(0)31 772 3840'
_publ_contact_author_phone     '+46(0)31 772 3843'
_publ_section_title
;
Degradation of silicone grease by Grignard reagents:
bis(μ-dimethylphenylsilanolato-κ²O:O)bis[bromido(diethyl
ether)magnesium(II)]
;
loop_
    _publ_author_name
    _publ_author_address
    'Lennartson, Anders'
;Department of Chemistry,
Göteborg University,
SE-412 96 Göteborg,
Sweden
;
    'Håkansson, Mikael'
;Department of Chemistry,
Göteborg University,
SE-412 96 Göteborg,
Sweden
;
