Supramolecular synthon polymorphism in 2 : 1 co-crystal of 4-hydroxybenzoic acid and 2,3,5,6-tetramethylpyrazine
Sreekanth, B. R.; Vishweshwar, Peddy; Vyas, K.; Chemical Communications (Cambridge, United Kingdom)  (2007) 2375–2377; doi:10.1039/b700082k

data_7113280
_publ_section_title
;
 Supramolecular synthon polymorphism in 2 : 1 co-crystal of
 4-hydroxybenzoic acid and 2,3,5,6-tetramethylpyrazine
;
_journal_coden_ASTM              CHCOFS
_journal_issue                   23
_journal_name_full
;
 Chemical Communications (Cambridge, United Kingdom)
;
_journal_page_first              2375
_journal_page_last               2377
_journal_paper_doi               10.1039/b700082k
_journal_year                    2007
_chemical_formula_moiety         'C8 H12 N2, 2(C7 H6 O3)'
_chemical_formula_sum            'C22 H24 N2 O6'
_chemical_formula_weight         412.44
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_cell_angle_alpha                90
_cell_angle_beta                 102.440(5)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   13.039(7)
_cell_length_b                   7.401(4)
_cell_length_c                   22.560(12)
_cell_measurement_reflns_used    7702
_cell_measurement_temperature    298
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      1.7
_cell_volume                     2126(2)
_computing_cell_refinement       CrystalClear
_computing_data_collection       CrystalClear
_computing_data_reduction        CrystalStructure
_computing_molecular_graphics    'X-seed 2.0'
_computing_publication_material  'CrystalStructure 3.6.0'
_computing_structure_refinement  CRYSTALS
_computing_structure_solution    SIR92
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.9771
_diffrn_measured_fraction_theta_max 0.9771
_diffrn_measurement_device_type  'Rigaku Mercury'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.060
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            24455
_diffrn_reflns_theta_full        27.51
_diffrn_reflns_theta_max         27.51
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_T_max  0.959
_exptl_absorpt_correction_T_min  0.956
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.289
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             872.00
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.45
_refine_diff_density_max         0.30
_refine_diff_density_min         -0.31
_refine_ls_extinction_coef       291.2(27)
_refine_ls_extinction_method
'Larson (1970) Crystallographic Computing eq. 22'
_refine_ls_goodness_of_fit_ref   0.886
_refine_ls_hydrogen_treatment    mixed
_refine_ls_number_parameters     602
_refine_ls_number_reflns         5150
_refine_ls_R_factor_gt           0.0540
_refine_ls_shift/su_max          0.1630
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
Chebychev polynomial with 3 parameters (Carruthers & Watkin, 1979)
7999.9600 10996.6000 3059.0400
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1210
_reflns_number_gt                1964
_reflns_number_total             5150
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_duplicate_entry             7101969
_cod_data_source_file            b700082k.txt
_cod_data_source_block           4HBA_TMP_form_1
_cod_original_cell_volume        2125.8(19)
_cod_original_formula_sum        'C22 H24 N2 O6 '
_cod_database_code               7113280