The crystal structure of 3-ammonio-4-aminobenzoate, C7H8N2O2 – a second polymorph
Hosten, Eric C.; Betz, Richard; Zeitschrift für Kristallographie - New Crystal Structures 236 (2021) 187–188; doi:10.1515/ncrs-2020-0510

data_8104918
_publ_section_title
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 The crystal structure of 3-ammonio-4-aminobenzoate, C7H8N2O2&#x00A0;-- a
 second polymorph
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_journal_issue                   1
_journal_name_full
'Zeitschrift f\"ur Kristallographie - New Crystal Structures'
_journal_page_first              187
_journal_page_last               188
_journal_paper_doi               10.1515/ncrs-2020-0510
_journal_volume                  236
_journal_year                    2021
_chemical_formula_moiety         'C7 H8 N2 O2'
_chemical_formula_sum            'C7 H8 N2 O2'
_chemical_formula_weight         152.15
_chemical_name_common            3-ammonio-4-aminobenzoate
_chemical_name_systematic        3-ammonio-4-aminobenzoate
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     SHELXS
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90
_cell_angle_beta                 95.400(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.9884(6)
_cell_length_b                   6.0490(4)
_cell_length_c                   12.1290(8)
_cell_measurement_reflns_used    2675
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      27.82
_cell_measurement_theta_min      2.70
_cell_volume                     656.54(8)
_computing_cell_refinement       'SAINT [1]'
_computing_data_collection       'APEX2 [1]'
_computing_data_reduction        'SAINT [1]'
_computing_molecular_graphics    'ORTEP3 [3], Mercury [4]'
_computing_publication_material  'SHELXL-97 [2], PLATON [5]'
_computing_structure_refinement  'SHELXL-97 [2]'
_computing_structure_solution    'SHELXS-97 [2]'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0192
_diffrn_reflns_av_sigmaI/netI    0.8087
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.991
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            5578
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.991
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.061
_diffrn_reflns_theta_min         2.703
_exptl_absorpt_coefficient_mu    0.116
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8087
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
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SADABS [6]                                         
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_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.539
_exptl_crystal_description       platelet
_exptl_crystal_F_000             320
_exptl_crystal_size_max          0.532
_exptl_crystal_size_mid          0.351
_exptl_crystal_size_min          0.106
_refine_diff_density_max         0.314
_refine_diff_density_min         -0.209
_refine_diff_density_rms         0.045
_refine_ls_extinction_coef       .
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     120
_refine_ls_number_reflns         1571
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0440
_refine_ls_R_factor_gt           0.0340
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0535P)^2^+0.2213P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0915
_refine_ls_wR_factor_ref         0.0978
_reflns_Friedel_coverage         0.000
_reflns_Friedel_fraction_full    .
_reflns_Friedel_fraction_max     .
_reflns_number_gt                1295
_reflns_number_total             1571
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            suppl_j_ncrs-2020-0510_suppl.cif
_cod_data_source_block           g
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               8104918
_iucr_geom_bonds_special_details
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<i>C<i>~g~(1) is the centroid of carbon atoms C2--C7.            
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