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_2012256
_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 H11 N4 O4 + , Cl O4 - , 3H2 O'
_chemical_formula_sum            'C16 H17 Cl N4 O11'
_chemical_formula_weight         476.79
_chemical_name_systematic
;6-carboxy-5-carboxylatopyrazine-2,3-diyldi-2-pyridinium perchlorate
 trihydrate
;
_space_group_IT_number           13
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yc'
_symmetry_space_group_name_H-M   'P 1 2/c 1'
_audit_creation_method           SHELXL97
_cell_angle_alpha                90
_cell_angle_beta                 106.934(8)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   6.1401(7)
_cell_length_b                   15.6358(12)
_cell_length_c                   10.7154(8)
_cell_measurement_reflns_used    5000
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      26.05
_cell_measurement_theta_min      1.65
_cell_volume                     984.13(16)
_computing_cell_refinement       'CELL (Stoe & Cie, 2000)'
_computing_data_collection       'EXPOSE (Stoe & Cie, 2000)'
_computing_data_reduction        'X-RED in STADI4 (Stoe & Cie, 1997)'
_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 0.82\%A
_diffrn_measured_fraction_theta_full .990
_diffrn_measured_fraction_theta_max .990
_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     .71073
_diffrn_reflns_av_R_equivalents  .033
_diffrn_reflns_av_sigmaI/netI    .028
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            7650
_diffrn_reflns_theta_full        25.94
_diffrn_reflns_theta_max         25.94
_diffrn_reflns_theta_min         2.38
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    .266
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.609
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             492
_exptl_crystal_size_max          .36
_exptl_crystal_size_mid          .35
_exptl_crystal_size_min          .26
_refine_diff_density_max         .18
_refine_diff_density_min         -.58
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     190
_refine_ls_number_reflns         1914
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.017
_refine_ls_R_factor_all          .057
_refine_ls_R_factor_gt           .040
_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^)+(0.0786P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .115
_reflns_number_gt                1419
_reflns_number_total             1914
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gd1159.cif
_cod_data_source_block           IIIa
_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 '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_cell_volume        984.13(15)
_cod_original_sg_symbol_H-M      'P 2/c'
_cod_database_code               2012256
_cod_database_fobs_code          2012256