3-Carboxypyridinium hydrogen oxalate
S. Athimoolam; S. Natarajan; Acta Crystallographica Section E 63 (2007) o963–o965; doi:10.1107/S1600536807003200

data_2212224
_publ_section_title
;
 3-Carboxypyridinium hydrogen oxalate
;
_journal_coeditor_code           HG2170
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o963
_journal_page_last               o965
_journal_paper_doi               10.1107/S1600536807003200
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C6 H6 N O2 +, C2 H O4 -'
_chemical_formula_moiety         'C6 H6 N O2 +, C2 H O4 -'
_chemical_formula_sum            'C8 H7 N O6'
_chemical_formula_weight         213.15
_chemical_name_common            '3-Carboxylpyridinium oxalate'
_chemical_name_systematic
;
3-carboxypyridinium oxalate
;
_space_group_IT_number           11
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yb'
_symmetry_space_group_name_H-M   'P 1 21/m 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXTL/PC
_cell_angle_alpha                90.00
_cell_angle_beta                 101.29(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.438(6)
_cell_length_b                   6.048(2)
_cell_length_c                   8.774(5)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13.76
_cell_measurement_theta_min      9.23
_cell_volume                     439.1(4)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection       'CAD-4 EXPRESS (Enraf--Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics
'MERCURY (Macrae <i>et al.</i>,  2006) and PLATON (Spek, 2003)'
_computing_publication_material  SHELXTL/PC
_computing_structure_refinement  SHELXTL/PC
_computing_structure_solution    'SHELXTL/PC (Bruker, 2000)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Enraf--Nonius MACH3 sealed-tube'
_diffrn_measurement_method       \w-2\q
_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  0.0239
_diffrn_reflns_av_sigmaI/netI    0.0159
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            1304
_diffrn_reflns_theta_full        27.0
_diffrn_reflns_theta_max         26.97
_diffrn_reflns_theta_min         2.37
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.142
_exptl_absorpt_correction_T_max  0.9779
_exptl_absorpt_correction_T_min  0.9597
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(North <i>et al.</i>,  1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.612
_exptl_crystal_density_meas      1.59(2)
_exptl_crystal_density_method
;
flotation using a mixture of xylene and bromoform
;
_exptl_crystal_description       plate
_exptl_crystal_F_000             220
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.248
_refine_diff_density_min         -0.264
_refine_ls_extinction_coef       0.029(8)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXTL/PC
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     101
_refine_ls_number_reflns         1046
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0463
_refine_ls_R_factor_gt           0.0375
_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^)+(0.0663P)^2^+0.0801P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1007
_refine_ls_wR_factor_ref         0.1080
_reflns_number_gt                865
_reflns_number_total             1046
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            hg2170.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/m'
_cod_database_code               2212224
_cod_database_fobs_code          2212224