Hydrogen bonding in the inner-salt zwitterion and in two different charged forms of 5,6-bis(2-pyridyl)pyrazine-2,3-dicarboxylic acid
Alfonso, Montserrat; Wang, Yi; Stoeckli-Evans, Helen; Acta Crystallographica Section C 57 (2001) 1184–1188; doi:10.1107/S0108270101010757

data_2012254
_publ_section_title
;
 Hydrogen bonding in the inner-salt zwitterion and in two different
 charged forms of 5,6-bis(2-pyridyl)pyrazine-2,3-dicarboxylic acid
;
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1184
_journal_page_last               1188
_journal_paper_doi               10.1107/S0108270101010757
_journal_volume                  57
_journal_year                    2001
_chemical_formula_moiety         'C16 H10 N4 O4'
_chemical_formula_sum            'C16 H10 N4 O4'
_chemical_formula_weight         322.28
_chemical_name_systematic
;
3-Carboxy-5-(2-pyridinio)-6-(2-pyridyl)pyrazine-2-carboxylate
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_audit_creation_method           SHELXL97
_cell_angle_alpha                90
_cell_angle_beta                 110.070(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.4770(10)
_cell_length_b                   13.523(2)
_cell_length_c                   10.0580(10)
_cell_measurement_reflns_used    20
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19
_cell_measurement_theta_min      14
_cell_volume                     1338.5(3)
_computing_cell_refinement       STADI4
_computing_data_collection       'STADI4 (Stoe & Cie, 1997)'
_computing_data_reduction        'X-RED in STADI4'
_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      293(2)
_diffrn_measured_fraction_theta_full .996
_diffrn_measured_fraction_theta_max .996
_diffrn_measurement_device_type  'Stoe four-circle'
_diffrn_measurement_method       2\q/\w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .039
_diffrn_reflns_av_sigmaI/netI    .109
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            2356
_diffrn_reflns_theta_full        24.98
_diffrn_reflns_theta_max         24.98
_diffrn_reflns_theta_min         2.07
_diffrn_standards_decay_%        <2
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    .119
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            pale_yellow
_exptl_crystal_density_diffrn    1.599
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             664
_exptl_crystal_size_max          .46
_exptl_crystal_size_mid          .30
_exptl_crystal_size_min          .11
_refine_diff_density_max         .17
_refine_diff_density_min         -.20
_refine_ls_extinction_coef       .014(2)
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_ref   .900
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     258
_refine_ls_number_reflns         2336
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      .900
_refine_ls_R_factor_all          .120
_refine_ls_R_factor_gt           .049
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.029P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .092
_reflns_number_gt                1227
_reflns_number_total             2336
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gd1159.cif
_cod_data_source_block           Ia
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2012254
_cod_database_fobs_code          2012254