3,3,6,6,9,9-Hexamethyl-2,3,4,5,6,7,8,9-octahydro-1<i>H</i>-xanthene-1,8-dione
Xie, Xiaofen; Zhang, Yuying; Liang, Jiefeng; Zhu, Yulin; Acta Crystallographica Section E 65 (2009) o219–; doi:10.1107/S1600536808042189

data_2220957
_publ_section_title
3,3,6,6,9,9-Hexamethyl-2,3,4,5,6,7,8,9-octahydro-1<i>H</i>-xanthene-1,8-dione
_journal_coeditor_code           ZL2156
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o219
_journal_paper_doi               10.1107/S1600536808042189
_journal_volume                  65
_journal_year                    2009
_chemical_formula_iupac          'C19 H26 O3'
_chemical_formula_moiety         'C19 H26 O3'
_chemical_formula_sum            'C19 H26 O3'
_chemical_formula_weight         302.40
_chemical_name_systematic
;
3,3,6,6,9,9-Hexamethyl-2,3,4,5,6,7,8,9-octahydro-1<i>H</i>-xanthene-1,8-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                 103.595(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   12.1688(19)
_cell_length_b                   11.7055(18)
_cell_length_c                   24.365(4)
_cell_measurement_reflns_used    3174
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      21.93
_cell_measurement_theta_min      2.46
_cell_volume                     3373.4(9)
_computing_cell_refinement       'SAINT (Bruker, 2004)'
_computing_data_collection       'APEX2 (Bruker, 2004)'
_computing_data_reduction        'SAINT (Bruker, 2004)'
_computing_molecular_graphics    'XP in SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.975
_diffrn_measured_fraction_theta_max 0.975
_diffrn_measurement_device_type  'Bruker APEXII 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  0.0423
_diffrn_reflns_av_sigmaI/netI    0.0573
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            20408
_diffrn_reflns_theta_full        27.89
_diffrn_reflns_theta_max         27.89
_diffrn_reflns_theta_min         1.72
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_T_max  0.981
_exptl_absorpt_correction_T_min  0.970
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2004)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.191
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1312.0
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.219
_refine_diff_density_min         -0.164
_refine_ls_extinction_coef       0.0012(4)
_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   1.054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     410
_refine_ls_number_reflns         7856
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.054
_refine_ls_R_factor_all          0.1147
_refine_ls_R_factor_gt           0.0583
_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^)+(0.0568P)^2^+0.7487P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1418
_refine_ls_wR_factor_ref         0.1645
_reflns_number_gt                4312
_reflns_number_total             7856
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            zl2156.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2220957
_cod_database_fobs_code          2220957