Solid state conformations of symmetrical aromatic biheterocycles: an X-ray crystallographic investigation.
Fitchett, Christopher M.; Richardson, Chris; Steel, Peter J.; Organic & biomolecular chemistry 3 (2005) 498–502; doi:10.1039/b416553e

data_7150048
_publ_section_title
;
 Solid state conformations of symmetrical aromatic biheterocycles: an
 X-ray crystallographic investigation.
;
_journal_issue                   3
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              498
_journal_page_last               502
_journal_paper_doi               10.1039/b416553e
_journal_volume                  3
_journal_year                    2005
_chemical_formula_moiety         'C16 H10 N4'
_chemical_formula_sum            'C16 H10 N4'
_chemical_formula_weight         258.28
_chemical_name_common            8
_chemical_name_systematic
;
2,2'-biquinoxaline
;
_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                 91.466(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   5.779(3)
_cell_length_b                   5.350(3)
_cell_length_c                   18.906(10)
_cell_measurement_temperature    163(2)
_cell_volume                     584.3(5)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      163(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0133
_diffrn_reflns_av_sigmaI/netI    0.0113
_diffrn_reflns_limit_h_max       5
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            6979
_diffrn_reflns_theta_full        26.36
_diffrn_reflns_theta_max         26.36
_diffrn_reflns_theta_min         2.16
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8245
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Blessing Acta Cryst. 1995(A51) 33-38'
_exptl_crystal_colour            Red
_exptl_crystal_density_diffrn    1.468
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             268
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.174
_refine_diff_density_min         -0.182
_refine_diff_density_rms         0.045
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     91
_refine_ls_number_reflns         1190
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0438
_refine_ls_R_factor_gt           0.0359
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0767P)^2^+0.0090P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1067
_refine_ls_wR_factor_ref         0.1112
_reflns_number_gt                954
_reflns_number_total             1190
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b416553e.txt
_cod_data_source_block           3cfh
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/adriana/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1555 2011-01-17 13:19:09Z saulius 
;
_cod_original_sg_symbol_H-M      P2(1)/n
_cod_database_code               7150048