Crystal structure of 6,6'-dimethyl-2<i>H</i>,2'<i>H</i>-3,4'-bichromene-2,2'-dione
Pujar, Kiran K.; Kulkarni, Manohar V.; Anil Kumar, G. N.; Acta Crystallographica Section E 70 (2014) 319–321; doi:10.1107/S1600536814021825

data_2240062
_publ_section_title
;
 Crystal structure of
 6,6'-dimethyl-2<i>H</i>,2'<i>H</i>-3,4'-bichromene-2,2'-dione
;
_journal_coeditor_code           IS5375
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              319
_journal_page_last               321
_journal_paper_doi               10.1107/S1600536814021825
_journal_volume                  70
_journal_year                    2014
_chemical_formula_iupac          'C20 H14 O4'
_chemical_formula_moiety         'C20 H14 O4'
_chemical_formula_sum            'C20 H14 O4'
_chemical_formula_weight         318.31
_chemical_name_systematic
;
6,6'-Dimethyl-2<i>H</i>,2'<i>H</i>-3,4'-bichromene-2,2'-dione
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                79.492(5)
_cell_angle_beta                 77.096(4)
_cell_angle_gamma                86.637(5)
_cell_formula_units_Z            2
_cell_length_a                   7.8340(10)
_cell_length_b                   8.0455(9)
_cell_length_c                   12.7952(15)
_cell_measurement_reflns_used    560
_cell_measurement_temperature    296(2)
_cell_measurement_theta_min      1.7
_cell_volume                     772.78(16)
_computing_cell_refinement
;
SAINT (Bruker, 1998)
;
_computing_data_collection
;
SMART (Bruker, 1998)
;
_computing_data_reduction
;
SAINT (Bruker, 1998)
;
_computing_molecular_graphics
;
ORTEP-3 for Windows (Farrugia, 2012) and CAMERON (Watkin <i>et al.</i>,
1996)
;
_computing_publication_material
;
PARST (Nardelli, 1996) and PLATON (Spek, 2009)
;
_computing_structure_refinement
;
SHELXL97 (Sheldrick, 2008)
;
_computing_structure_solution
;
SIR92 (Altomare <i>et al.</i>,  1993)
;
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker SMART CCD area-detector'
_diffrn_measurement_method       '\f 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  0.0272
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            12862
_diffrn_reflns_reduction_process
;
;
_diffrn_reflns_theta_full        27.44
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         1.66
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.964
_exptl_absorpt_correction_T_min  0.954
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
(SADABS; Sheldrick, 1996)
;
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.368
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             332
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.19
_refine_diff_density_min         -0.202
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.049
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     219
_refine_ls_number_reflns         3499
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0656
_refine_ls_R_factor_gt           0.0455
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0661P)^2^+0.1433P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1238
_refine_ls_wR_factor_ref         0.1397
_reflns_number_gt                2509
_reflns_number_total             3499
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            is5375sup1.cif
_cod_data_source_block           I
_cod_database_code               2240062
_cod_database_fobs_code          2240062