2,7-Diacetylxanthene
Li, Wu; Ai-Lin, Liu; Yang, Lu; Guan-Hua, Du; Acta Crystallographica Section E 62 (2006) o1770–o1771; doi:10.1107/S1600536806012050

data_2209026
_publ_section_title
;
 2,7-Diacetylxanthene
;
_journal_coeditor_code           WK2007
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1770
_journal_page_last               o1771
_journal_paper_doi               10.1107/S1600536806012050
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C17 H14 O3'
_chemical_formula_moiety         'C17 H14 O3'
_chemical_formula_sum            'C17 H14 O3'
_chemical_formula_weight         266.28
_chemical_name_systematic
;
2,7-diacetylxanthene
;
_space_group_IT_number           36
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'C 2c -2'
_symmetry_space_group_name_H-M   'C m c 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   29.875(6)
_cell_length_b                   6.0270(12)
_cell_length_c                   7.2560(15)
_cell_measurement_reflns_used    1899
_cell_measurement_temperature    296.0(10)
_cell_measurement_theta_max      27.27
_cell_measurement_theta_min      2.73
_cell_volume                     1306.5(5)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'DENZO (Otwinowski & Minor, 1997)'
_computing_data_reduction        SCALEPACK
_computing_molecular_graphics
'ORTEPII (Johnson, 1976) and PLATON (Spek, 2003)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      296.0(10)
_diffrn_detector_area_resol_mean 0
_diffrn_measured_fraction_theta_full 0.977
_diffrn_measured_fraction_theta_max 0.968
_diffrn_measurement_device_type  'MAC DIP 2030K'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0226
_diffrn_reflns_av_sigmaI/netI    0.0214
_diffrn_reflns_limit_h_max       38
_diffrn_reflns_limit_h_min       -37
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            1899
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.27
_diffrn_reflns_theta_min         2.73
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.354
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             560
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.111
_refine_diff_density_min         -0.113
_refine_ls_extinction_coef       0.010(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.110
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     95
_refine_ls_number_reflns         785
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.109
_refine_ls_R_factor_all          0.0499
_refine_ls_R_factor_gt           0.0479
_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^)+(0.0667P)^2^+0.4024P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1258
_refine_ls_wR_factor_ref         0.1281
_reflns_number_gt                782
_reflns_number_total             785
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            wk2007.cif
_cod_data_source_block           I
_cod_database_code               2209026
_cod_database_fobs_code          2209026