5,8-Dimethoxy-2,3-bis(2-pyridyl)quinoxaline
Xiao-Jun Zhao; Miao Du; Acta Crystallographica Section C 59 (2003) o496–o498; doi:10.1107/S0108270103015750

data_2013446
_publ_section_title
;
 5,8-Dimethoxy-2,3-bis(2-pyridyl)quinoxaline
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o496
_journal_page_last               o498
_journal_paper_doi               10.1107/S0108270103015750
_journal_volume                  59
_journal_year                    2003
_chemical_formula_iupac          'C20 H16 N4 O2'
_chemical_formula_moiety         'C20 H16 N4 O2'
_chemical_formula_sum            'C20 H16 N4 O2'
_chemical_formula_weight         344.37
_chemical_name_systematic
;
5,8-dimethoxy-2,3-bis(2-pyridyl)quinoxaline
;
_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'
_cell_angle_alpha                90.00
_cell_angle_beta                 95.958(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.0626(11)
_cell_length_b                   17.355(3)
_cell_length_c                   13.674(2)
_cell_measurement_reflns_used    6907
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.02
_cell_measurement_theta_min      1.90
_cell_volume                     1667.0(5)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (BRUKER, 1998)'
_computing_data_reduction        'SAINT (BRUKER, 1998)'
_computing_molecular_graphics    'XP (Bruker, 1998)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device       'BRUKER SMART 1000'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0316
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            6907
_diffrn_reflns_theta_full        25.02
_diffrn_reflns_theta_max         25.02
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count none
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.986
_exptl_absorpt_correction_T_min  0.967
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SAINT (Bruker 1998) and SADABS (Sheldrick, 1997)'
_exptl_crystal_colour            'light yellow'
_exptl_crystal_density_diffrn    1.372
_exptl_crystal_density_meas      ?
_exptl_crystal_description       block
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.200
_refine_diff_density_min         -0.147
_refine_ls_extinction_coef       0.0213(19)
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     236
_refine_ls_number_reflns         2954
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0586
_refine_ls_R_factor_gt           0.0383
_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^)+(0.06P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0964
_refine_ls_wR_factor_ref         0.1075
_reflns_number_gt                2125
_reflns_number_total             2954
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ga1023.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/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 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/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_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' 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_Hall     -p_2yn
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2013446
_cod_database_fobs_code          2013446