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###        Electronic paper (Acta Crystallographica Section E)             ###
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#                                                                            #
# This CIF contains the data in a paper accepted for publication in Acta     #
# Crystallographica Section E. It conforms to the requirements of Notes      #
# for Authors for Section E, 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/  #
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#                                                                            #
#            Copyright International Union of Crystallography                #
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data_I
_audit_creation_method     SHELXL-97
_chemical_name_systematic
;
N,N'-Bis[1-(4-pyridyl)ethylidene]-p-phenylenediamine
;
_chemical_name_common     ?
_chemical_formula_moiety     'C20 H18 N4'
_chemical_formula_sum     'C20 H18 N4'
_chemical_formula_iupac     'C20 H18 N4'
_chemical_formula_weight     314.38
_chemical_melting_point     '198-200 deg. C'
_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     5.8900(3)
_cell_length_b     8.0690(3)
_cell_length_c     8.8480(5)
_cell_angle_alpha     94.7670(18)
_cell_angle_beta     92.0520(18)
_cell_angle_gamma     104.1570(17)
_cell_volume     405.65(3)
_cell_formula_units_Z     1
_cell_measurement_reflns_used     1279
_cell_measurement_theta_min     3.32
_cell_measurement_theta_max     27.88
_cell_measurement_temperature     110(2)
_exptl_crystal_description     'prism'
_exptl_crystal_colour     'light brown'
_exptl_crystal_size_max     0.35
_exptl_crystal_size_mid     0.20
_exptl_crystal_size_min     0.20
_exptl_crystal_density_diffrn     1.287
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     166
_exptl_absorpt_coefficient_mu     0.079
_exptl_absorpt_correction_type     none
_exptl_absorpt_process_details     ?
_exptl_absorpt_correction_T_min     ?
_exptl_absorpt_correction_T_max     ?
_exptl_special_details
;
 ?
;
_diffrn_ambient_temperature     110(2)
_diffrn_radiation_type     MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_radiation_source     'fine-focus sealed tube'
_diffrn_radiation_monochromator     graphite
_diffrn_measurement_device_type     'Nonius KappaCCD'
_diffrn_measurement_method     'φ and ω'
_diffrn_detector_area_resol_mean     '56 microns'
_diffrn_reflns_number     1775
_diffrn_reflns_av_R_equivalents     0.0000
_diffrn_reflns_av_sigmaI/netI     0.0530
_diffrn_reflns_theta_min     3.32
_diffrn_reflns_theta_max     27.88
_diffrn_reflns_theta_full     24.98
_diffrn_measured_fraction_theta_max     0.953
_diffrn_measured_fraction_theta_full     0.953
_diffrn_reflns_limit_h_min     0
_diffrn_reflns_limit_h_max     7
_diffrn_reflns_limit_k_min     -10
_diffrn_reflns_limit_k_max     10
_diffrn_reflns_limit_l_min     -11
_diffrn_reflns_limit_l_max     11
_diffrn_standards_number     0
_diffrn_standards_interval_count     ?
_diffrn_standards_interval_time     ?
_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     1775
_reflns_number_gt     1279
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all     0.0769
_refine_ls_R_factor_gt     0.0482
_refine_ls_wR_factor_gt     0.1295
_refine_ls_wR_factor_ref     0.1529
_refine_ls_goodness_of_fit_ref     0.884
_refine_ls_restrained_S_all     0.884
_refine_ls_number_reflns     1775
_refine_ls_number_parameters     110
_refine_ls_number_restraints     0
_refine_ls_hydrogen_treatment     constr
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
     'calc w = 1/[σ²(Fo²)+(0.0943P)²+0.2375P] 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     0.017
_refine_ls_shift/su_mean     0.002
_refine_diff_density_max     0.219
_refine_diff_density_min     -0.226
_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'
    'N' 'N' 0.0061 0.0033
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'COLLECT (Nonius, 1999)'
_computing_cell_refinement     'DENZO (Otwinowski, 1985)'
_computing_data_reduction     'DENZO'
_computing_structure_solution     'SIR92 (Altomare et al., 1994)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'ORTEPIII (Burnett & Johnson, 1996)'
_computing_publication_material     'SHELXL97'
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
    N1 0.7027(3) 0.84831(19) 0.46098(17) 0.0251(4) Uani d . 1 . . N
    C2 0.4989(3) 0.8073(2) 0.3773(2) 0.0252(4) Uani d . 1 . . C
    H2 0.4084 0.8900 0.3778 0.030 Uiso calc R 1 . . H
    C3 0.8263(3) 0.7294(2) 0.45633(19) 0.0222(4) Uani d . 1 . . C
    H3 0.9726 0.7555 0.5132 0.027 Uiso calc R 1 . . H
    C4 0.7534(3) 0.5697(2) 0.37323(19) 0.0199(4) Uani d . 1 . . C
    H4 0.8481 0.4899 0.3743 0.024 Uiso calc R 1 . . H
    C5 0.5401(3) 0.5280(2) 0.28844(18) 0.0169(4) Uani d . 1 . . C
    C6 0.4123(3) 0.6529(2) 0.2907(2) 0.0227(4) Uani d . 1 . . C
    H6 0.2672 0.6317 0.2331 0.027 Uiso calc R 1 . . H
    C7 0.4466(3) 0.3570(2) 0.20043(19) 0.0186(4) Uani d . 1 . . C
    C8 0.6123(3) 0.2431(2) 0.1772(3) 0.0338(5) Uani d . 1 . . C
    H8A 0.6386 0.1950 0.2726 0.051 Uiso calc R 1 . . H
    H8B 0.7620 0.3105 0.1455 0.051 Uiso calc R 1 . . H
    H8C 0.5443 0.1496 0.0985 0.051 Uiso calc R 1 . . H
    N9 0.2324(2) 0.32075(17) 0.15220(16) 0.0194(3) Uani d . 1 . . N
    C10 0.1237(3) 0.1575(2) 0.07524(18) 0.0169(4) Uani d . 1 . . C
    C11 0.0548(3) 0.1448(2) -0.07819(18) 0.0201(4) Uani d . 1 . . C
    H11 0.0912 0.2442 -0.1320 0.024 Uiso calc R 1 . . H
    C12 0.0661(3) 0.0107(2) 0.15348(19) 0.0208(4) Uani d . 1 . . C
    H12 0.1101 0.0177 0.2586 0.025 Uiso calc R 1 . . H
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
    N1 0.0269(9) 0.0218(8) 0.0248(8) 0.0049(6) -0.0007(6) -0.0034(6)
    C2 0.0238(9) 0.0188(9) 0.0329(10) 0.0077(7) -0.0007(7) -0.0034(8)
    C3 0.0213(9) 0.0233(9) 0.0198(8) 0.0030(7) -0.0032(7) -0.0009(7)
    C4 0.0186(9) 0.0200(9) 0.0214(8) 0.0050(6) 0.0003(6) 0.0031(7)
    C5 0.0159(8) 0.0163(8) 0.0173(8) 0.0019(6) 0.0022(6) 0.0008(6)
    C6 0.0185(9) 0.0214(9) 0.0270(9) 0.0046(6) -0.0029(7) -0.0022(7)
    C7 0.0165(8) 0.0181(8) 0.0204(8) 0.0036(6) 0.0008(6) 0.0001(7)
    C8 0.0197(9) 0.0255(10) 0.0534(13) 0.0069(7) -0.0026(9) -0.0145(9)
    N9 0.0181(7) 0.0156(7) 0.0233(7) 0.0038(5) -0.0023(6) -0.0027(6)
    C10 0.0136(8) 0.0145(8) 0.0218(8) 0.0044(6) -0.0012(6) -0.0036(6)
    C11 0.0220(9) 0.0168(8) 0.0206(8) 0.0030(6) 0.0001(7) 0.0018(7)
    C12 0.0229(9) 0.0216(9) 0.0176(8) 0.0064(7) -0.0014(6) -0.0007(7)
_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
    N1 C2 . 1.342(2) ?
    N1 C3 . 1.338(2) ?
    C2 C6 . 1.380(2) ?
    C2 H2 . 0.950 ?
    C3 C4 . 1.391(2) ?
    C3 H3 . 0.950 ?
    C4 C5 . 1.392(2) ?
    C4 H4 . 0.950 ?
    C5 C6 . 1.397(2) ?
    C5 C7 . 1.494(2) ?
    C6 H6 . 0.950 ?
    C7 N9 . 1.273(2) ?
    C7 C8 . 1.503(2) ?
    C8 H8A . 0.980 ?
    C8 H8B . 0.980 ?
    C8 H8C . 0.980 ?
    N9 C10 . 1.420(2) ?
    C10 C11 . 1.391(2) ?
    C10 C12 . 1.398(2) ?
    C11 C12 2 1.384(2) ?
    C11 H11 . 0.950 ?
    C12 C11 2 1.384(2) ?
    C12 H12 . 0.950 ?
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 N1 C3 . . 116.17(15) ?
    N1 C2 C6 . . 124.20(16) ?
    N1 C2 H2 . . 117.9 ?
    C6 C2 H2 . . 117.9 ?
    N1 C3 C4 . . 123.92(16) ?
    N1 C3 H3 . . 118.0 ?
    C4 C3 H3 . . 118.0 ?
    C3 C4 C5 . . 119.30(15) ?
    C3 C4 H4 . . 120.3 ?
    C5 C4 H4 . . 120.3 ?
    C4 C5 C6 . . 117.03(15) ?
    C4 C5 C7 . . 122.34(15) ?
    C6 C5 C7 . . 120.62(15) ?
    C2 C6 C5 . . 119.36(16) ?
    C2 C6 H6 . . 120.3 ?
    C5 C6 H6 . . 120.3 ?
    N9 C7 C5 . . 116.66(15) ?
    N9 C7 C8 . . 125.86(15) ?
    C5 C7 C8 . . 117.48(14) ?
    C7 C8 H8A . . 109.5 ?
    C7 C8 H8B . . 109.5 ?
    H8A C8 H8B . . 109.5 ?
    C7 C8 H8C . . 109.5 ?
    H8A C8 H8C . . 109.5 ?
    H8B C8 H8C . . 109.5 ?
    C7 N9 C10 . . 120.88(14) ?
    C11 C10 C12 . . 118.95(15) ?
    C11 C10 N9 . . 119.64(14) ?
    C12 C10 N9 . . 121.18(15) ?
    C12 C11 C10 2 . 120.86(15) ?
    C12 C11 H11 2 . 119.6 ?
    C10 C11 H11 . . 119.6 ?
    C11 C12 C10 2 . 120.18(15) ?
    C11 C12 H12 2 . 119.9 ?
    C10 C12 H12 . . 119.9 ?
data_global
_journal_date_recd_electronic     2002-04-02
_journal_date_accepted     2002-04-08
_journal_name_full     'Acta Crystallographica, Section E'
_journal_year     2002
_journal_volume     58
_journal_issue      5
_journal_page_first     o528
_journal_page_last     o529
_journal_paper_category     EO
_publ_contact_author_name     'Professor Israel Goldberg'
_publ_contact_author_address
;
School of Chemistry
Tel-Aviv University
Ramat-Aviv
69978 Tel-Aviv
Israel
;
_publ_contact_author_email     goldberg@post.tau.ac.il
_publ_contact_author_fax     '972 3 6409293'
_publ_contact_author_phone     '972 3 6409965'
_publ_section_title
;
N,N'-Bis[1-(4-pyridyl)ethylidene]-p-phenylenediamine
;
loop_
    _publ_author_name
    _publ_author_address
    'Goutam Kumar Patra'
;     School of Chemistry
      Sackler Faculty of Exact Sciences
      Tel-Aviv University
      Ramat-Aviv
      69978 Tel-Aviv
      Israel
;
    'Israel Goldberg'
;     School of Chemistry
      Sackler Faculty of Exact Sciences
      Tel-Aviv University
      Ramat-Aviv
      69978 Tel-Aviv
      Israel
;
