7,7',8,8'-Tetramethoxy-4,4'-dimethyl-3,5'-bichromene-2,2'-dione
Fun, Hoong-Kun; Jebas, Samuel Robinson; Parveen, Mehtab; Khanam, Zakia; Ghalib, Raza Murad; Acta Crystallographica Section E 65 (2009) o1322–o1323; doi:10.1107/S1600536809018029

data_2222102
_publ_section_title
;
 7,7',8,8'-Tetramethoxy-4,4'-dimethyl-3,5'-bichromene-2,2'-dione
;
_journal_coeditor_code           LH2822
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1322
_journal_page_last               o1323
_journal_paper_doi               10.1107/S1600536809018029
_journal_volume                  65
_journal_year                    2009
_chemical_formula_iupac          'C24 H22 O8'
_chemical_formula_moiety         'C24 H22 O8'
_chemical_formula_sum            'C24 H22 O8'
_chemical_formula_weight         438.42
_chemical_name_systematic
;
7,7',8,8'-Tetramethoxy-4,4'-dimethyl-3,5'-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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 96.2540(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.47240(10)
_cell_length_b                   23.4766(3)
_cell_length_c                   9.35250(10)
_cell_measurement_reflns_used    9875
_cell_measurement_temperature    100
_cell_measurement_theta_max      33.02
_cell_measurement_theta_min      2.71
_cell_volume                     2067.43(4)
_computing_cell_refinement       'SAINT (Bruker, 2005)'
_computing_data_collection       'APEX2 (Bruker, 2005)'
_computing_data_reduction        'SAINT (Bruker, 2005)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material
'SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009)'
_computing_structure_refinement  'SHELXTL (Sheldrick, 2008)'
_computing_structure_solution    'SHELXTL (Sheldrick, 2008)'
_diffrn_ambient_temperature      100
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker SMART 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  0.0302
_diffrn_reflns_av_sigmaI/netI    0.0190
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       34
_diffrn_reflns_limit_k_min       -34
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            58385
_diffrn_reflns_theta_full        31.74
_diffrn_reflns_theta_max         31.74
_diffrn_reflns_theta_min         1.73
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.106
_exptl_absorpt_correction_T_max  0.9847
_exptl_absorpt_correction_T_min  0.9490
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2005)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.409
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.468
_refine_diff_density_min         -0.235
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.069
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     295
_refine_ls_number_reflns         7006
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.069
_refine_ls_R_factor_all          0.0547
_refine_ls_R_factor_gt           0.0462
_refine_ls_shift/su_max_lt       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^)+(0.0593P)^2^+0.8142P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1194
_refine_ls_wR_factor_ref         0.1249
_reflns_number_gt                6023
_reflns_number_total             7006
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lh2822.cif
_cod_data_source_block           I
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2222102
_cod_database_fobs_code          2222102