4,5-Dimethoxycyclopent-4-ene-1,2,3-trione
Chen, Hong-Yu; Fang, Qi; Xue, Gang; Yu, Wen-Tao; Acta Crystallographica Section E 61 (2005) o2696–o2698; doi:10.1107/S1600536805023068

data_2206534
_publ_section_title
;
 4,5-Dimethoxycyclopent-4-ene-1,2,3-trione
;
_journal_coeditor_code           RZ6103
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2696
_journal_page_last               o2698
_journal_paper_doi               10.1107/S1600536805023068
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C7 H6 O5'
_chemical_formula_moiety         'C7 H6 O5'
_chemical_formula_sum            'C7 H6 O5'
_chemical_formula_weight         170.12
_chemical_name_systematic
;
4,5-Dimethoxycyclopent-4-ene-1,2,3-trione
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.000
_cell_angle_beta                 90.000
_cell_angle_gamma                90.000
_cell_formula_units_Z            4
_cell_length_a                   7.181(5)
_cell_length_b                   8.069(5)
_cell_length_c                   13.015(5)
_cell_measurement_reflns_used    38
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      12.475
_cell_measurement_theta_min      5.330
_cell_volume                     754.1(8)
_computing_cell_refinement       XSCANS
_computing_data_collection       'XSCANS (Bruker,1996)'
_computing_data_reduction        XSCANS
_computing_molecular_graphics    'SHELXTL (Bruker, 1997)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Altomare et al., 1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0446
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_diffrn_reflns_limit_h_min       -9
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_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            2052
_diffrn_reflns_theta_full        27.49
_diffrn_reflns_theta_max         27.49
_diffrn_reflns_theta_min         2.97
_diffrn_standards_decay_%        1
_diffrn_standards_interval_count 3
_diffrn_standards_number         97
_exptl_absorpt_coefficient_mu    0.131
_exptl_absorpt_correction_T_max  0.9705
_exptl_absorpt_correction_T_min  0.8804
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   '(XSCANS; Bruker, 1996)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.498
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             352
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.134
_refine_diff_density_min         -0.138
_refine_ls_extinction_coef       0.149(14)
_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   0.944
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     110
_refine_ls_number_reflns         1026
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.944
_refine_ls_R_factor_all          0.0883
_refine_ls_R_factor_gt           0.0404
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0525P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0905
_refine_ls_wR_factor_ref         0.1171
_reflns_number_gt                512
_reflns_number_total             1026
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            rz6103.cif
_cod_data_source_block           I
_cod_database_code               2206534
_cod_database_fobs_code          2206534