3,4-Difluoro-2-hydroxybenzoic acid
Ravi Kiran, Bhaskarachar; Palakshamurthy, Bandrehalli Siddagangaiah; Vijayakumar, Giriyapura R.; Bharath, Hebbur Shivamurthy; Acta Crystallographica Section E 70 (2014) o519–; doi:10.1107/S1600536814007211

data_2239291
_publ_section_title
;
 3,4-Difluoro-2-hydroxybenzoic acid
;
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o519
_journal_paper_doi               10.1107/S1600536814007211
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'C7 H4 F2 O3'
_chemical_formula_moiety         'C7 H4 F2 O3'
_chemical_formula_sum            'C7 H4 F2 O3'
_chemical_formula_weight         174.10
_chemical_melting_point          448
_chemical_name_systematic
;
3,4-Difluoro-2-hydroxybenzoic acid
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 106.257(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.4252(8)
_cell_length_b                   6.8145(5)
_cell_length_c                   11.0391(8)
_cell_measurement_reflns_used    1045
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      26.5
_cell_measurement_theta_min      2.3
_cell_volume                     680.67(9)
_computing_cell_refinement       'APEX2 and SAINT-Plus (Bruker, 2009)'
_computing_data_collection       'APEX2 (Bruker, 2009)'
_computing_data_reduction        'SAINT-Plus and XPREP (Bruker, 2009)'
_computing_molecular_graphics
'ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae <i>et al.</i>, 2008)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_detector_area_resol_mean 1.6
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEXII CCD area-detector'
_diffrn_measurement_method       'phi and \w scans'
_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  0.0365
_diffrn_reflns_av_sigmaI/netI    0.0698
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            6362
_diffrn_reflns_theta_full        25.99
_diffrn_reflns_theta_max         25.99
_diffrn_reflns_theta_min         2.52
_diffrn_standards_decay_%        1.2
_diffrn_standards_interval_count 22
_diffrn_standards_interval_time  15
_diffrn_standards_number         1344
_exptl_absorpt_coefficient_mu    0.167
_exptl_absorpt_correction_T_max  0.9803
_exptl_absorpt_correction_T_min  0.9674
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2007)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.699
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             352
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.193
_refine_diff_density_min         -0.140
_refine_ls_extinction_coef       0.018(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.086
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     112
_refine_ls_number_reflns         1344
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.086
_refine_ls_R_factor_all          0.0818
_refine_ls_R_factor_gt           0.0307
_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^)+(0.0514P)^2^+0.0514P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0900
_refine_ls_wR_factor_ref         0.0944
_reflns_number_gt                1045
_reflns_number_total             1344
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            jj2185sup1.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2239291
_cod_database_fobs_code          2239291