7,7'-Dihydroxy-4,4'-dimethyl-3,4-dihydro-2<i>H</i>,2'<i>H</i>-4,6'-bichromene-2,2'-dione
Pereira Silva, P. S.; Parveen, Mehtab; Ali, Akhtar; Malla, Ali Mohammed; Ramos Silva, M.; Acta Crystallographica Section E 67 (2011) o201–; doi:10.1107/S160053681005244X

data_2228672
_publ_section_title
;
 7,7'-Dihydroxy-4,4'-dimethyl-3,4-dihydro-2<i>H</i>,2'<i>H</i>-4,6'-bichromene-2,2'-dione
;
_journal_coeditor_code           BT5436
_journal_issue                   1
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o201
_journal_paper_doi               10.1107/S160053681005244X
_journal_volume                  67
_journal_year                    2011
_chemical_formula_iupac          'C20 H16 O6'
_chemical_formula_moiety         'C20 H16 O6'
_chemical_formula_sum            'C20 H16 O6'
_chemical_formula_weight         352.33
_chemical_melting_point          578
_chemical_name_systematic
;
7,7'-Dihydroxy-4,4'-dimethyl-3,4-dihydro-2<i>H</i>,2'<i>H</i>-
4,6'-bichromene-2,2'-dione
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 110.8700(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.0432(2)
_cell_length_b                   11.5111(2)
_cell_length_c                   17.2212(4)
_cell_measurement_reflns_used    6612
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.8903
_cell_measurement_theta_min      2.5315
_cell_volume                     1675.06(6)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 2003)'
_computing_data_reduction        'SAINT (Bruker, 2003)'
_computing_molecular_graphics    'PLATON (Spek, 2009)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEXII CCD area-detector'
_diffrn_measurement_method       '\f and \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  0.0317
_diffrn_reflns_av_sigmaI/netI    0.0176
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            44743
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         29.01
_diffrn_reflns_theta_min         2.18
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.104
_exptl_absorpt_correction_T_max  0.977
_exptl_absorpt_correction_T_min  0.863
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2003)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.397
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             736
_exptl_crystal_size_max          0.39
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.235
_refine_diff_density_min         -0.185
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     239
_refine_ls_number_reflns         4457
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0544
_refine_ls_R_factor_gt           0.0404
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0494P)^2^+0.3328P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1011
_refine_ls_wR_factor_ref         0.1090
_reflns_number_gt                3459
_reflns_number_total             4457
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            bt5436.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2228672
_cod_database_fobs_code          2228672