The inner-salt zwitterion, the dihydrochloride dihydrate and the dimethyl sulfoxide disolvate of 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic acid
Wang, Yi; Stoeckli-Evans, Helen; Acta Crystallographica Section C 68 (2012) o431–o435; doi:10.1107/S0108270112039534

data_2018632
_publ_section_title
;
 The inner-salt zwitterion, the dihydrochloride dihydrate and the dimethyl
 sulfoxide disolvate of 3,6-bis(pyridin-2-yl)pyrazine-2,5-dicarboxylic
 acid
;
_journal_coeditor_code           FG3272
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o431
_journal_page_last               o435
_journal_paper_doi               10.1107/S0108270112039534
_journal_volume                  68
_journal_year                    2012
_chemical_formula_iupac          'C16 H12 N4 O4 2+ , 2Cl - , 2H2 O'
_chemical_formula_moiety         'C16 H12 N4 O4 2+, 2(Cl -), 2(H2 O)'
_chemical_formula_sum            'C16 H16 Cl2 N4 O6'
_chemical_formula_weight         431.23
_chemical_name_systematic
;
2,2'-(3,6-Dicarboxypyrazine-2,5-diyl)bis(pyridin-1-ium) dichloride dihydrate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                63.400(10)
_cell_angle_beta                 81.940(10)
_cell_angle_gamma                87.470(10)
_cell_formula_units_Z            1
_cell_length_a                   6.8570(10)
_cell_length_b                   8.5760(10)
_cell_length_c                   9.187(2)
_cell_measurement_reflns_used    21
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      20.0
_cell_measurement_theta_min      14.0
_cell_volume                     478.19(14)
_computing_cell_refinement       'STADI-4 Software (Stoe & Cie, 1997)'
_computing_data_collection       'STADI-4 Software (Stoe & Cie, 1997)'
_computing_data_reduction        'X-RED (Stoe & Cie, 1997)'
_computing_molecular_graphics
;
PLATON (Spek, 2009) and Mercury (Macrae <i>et al.</i>, 2008)
;
_computing_publication_material
;
SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and
publCIF (Westrip, 2010)
;
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      213(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Stoe AED-2 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     0.71073
_diffrn_reflns_av_R_equivalents  0.0354
_diffrn_reflns_av_sigmaI/netI    0.0394
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3504
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.50
_diffrn_standards_decay_%        7
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.381
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.497
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             222
_exptl_crystal_size_max          0.49
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.27
_refine_diff_density_max         0.271
_refine_diff_density_min         -0.323
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.023
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     143
_refine_ls_number_reflns         1681
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.023
_refine_ls_R_factor_all          0.0399
_refine_ls_R_factor_gt           0.0338
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0596P)^2^+0.0431P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0887
_refine_ls_wR_factor_ref         0.0927
_reflns_number_gt                1463
_reflns_number_total             1681
_reflns_threshold_expression     I>2\(I)
_cod_data_source_file            fg3272.cif
_cod_data_source_block           Ib
_cod_database_code               2018632
_cod_database_fobs_code          2018632