A monoclinic polymorph of 2,3,2',3'-tetrakis(2-pyridyl)-6,6'-biquinoxalinyl
Antonia Neels; Helen Stoeckli-Evans; Acta Crystallographica Section E 59 (2003) o2028–o2029; doi:10.1107/S1600536803026977

data_2202764
_publ_section_title
;
 A monoclinic polymorph of
 2,3,2',3'-tetrakis(2-pyridyl)-6,6'-biquinoxalinyl
;
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2028
_journal_page_last               o2029
_journal_paper_doi               10.1107/S1600536803026977
_journal_volume                  59
_journal_year                    2003
_chemical_formula_iupac          'C36 H22 N8'
_chemical_formula_moiety         'C36 H22 N8'
_chemical_formula_sum            'C36 H22 N8'
_chemical_formula_weight         566.62
_chemical_name_systematic
;
2,3,2',3'-tetrakis(2-pyridyl)-6,6'-biquinoxalinyl
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 97.024(11)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.8892(6)
_cell_length_b                   7.7255(6)
_cell_length_c                   26.895(2)
_cell_measurement_reflns_used    2327
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      25.90
_cell_measurement_theta_min      2.28
_cell_volume                     1420.7(2)
_computing_cell_refinement       'CELL (Stoe, 2000)'
_computing_data_collection       'EXPOSE (Stoe, 2000)'
_computing_data_reduction        'INTEGRATE (Stoe, 2000)'
_computing_molecular_graphics    'PLATON99 (Spek, 1990)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      223(2)
_diffrn_detector_area_resol_mean 0.81\%A
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'STOE IPDS'
_diffrn_measurement_method       '\f oscillation'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1325
_diffrn_reflns_av_sigmaI/netI    0.1424
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            10763
_diffrn_reflns_theta_full        25.94
_diffrn_reflns_theta_max         25.94
_diffrn_reflns_theta_min         2.74
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.325
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             588
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.136
_refine_diff_density_min         -0.155
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.725
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     199
_refine_ls_number_reflns         2771
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.725
_refine_ls_R_factor_all          0.1419
_refine_ls_R_factor_gt           0.0418
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         <0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0319P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0760
_refine_ls_wR_factor_ref         0.0961
_reflns_number_gt                1024
_reflns_number_total             2771
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            na6273.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'none' was changed to '?' - the
value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2202764
_cod_database_fobs_code          2202764