Redetermination of 7,8-dihydroxy-2<i>H</i>-chromen-2-one hemihydrate
Yong-Bin Lu; Qi-Tai Zheng; Yang Lu; Acta Crystallographica Section E 62 (2006) o5315–o5316; doi:10.1107/S1600536806036919

data_2210849
_publ_section_title
;
 Redetermination of 7,8-dihydroxy-2<i>H</i>-chromen-2-one hemihydrate
;
_journal_coeditor_code           AC2044
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o5315
_journal_page_last               o5316
_journal_paper_doi               10.1107/S1600536806036919
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C9 H6 O4, 0.5H2 O'
_chemical_formula_moiety         'C9 H6 O4, 0.5H2 O'
_chemical_formula_sum            'C9 H7 O4.5'
_chemical_formula_weight         187.15
_chemical_name_common            Daphnetin
_chemical_name_systematic
;
7,8-dihydroxy-2H-chromen-2-one hemihydrate
;
_space_group_IT_number           43
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'F 2 -2d'
_symmetry_space_group_name_H-M   'F d d 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            16
_cell_length_a                   22.990(3)
_cell_length_b                   36.609(5)
_cell_length_c                   3.711(3)
_cell_measurement_reflns_used    1066
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      27.99
_cell_measurement_theta_min      2.84
_cell_volume                     3123(3)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'DENZO (Otwinowski & Minor, 1997)'
_computing_data_reduction        SCALEPACK
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  SHELXL97
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_detector_area_resol_mean 0
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_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  0.0450
_diffrn_reflns_av_sigmaI/netI    0.0580
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -30
_diffrn_reflns_limit_k_max       46
_diffrn_reflns_limit_k_min       -46
_diffrn_reflns_limit_l_max       4
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            3924
_diffrn_reflns_theta_full        27.99
_diffrn_reflns_theta_max         27.99
_diffrn_reflns_theta_min         2.84
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.130
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.592
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1552
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.197
_refine_diff_density_min         -0.218
_refine_ls_extinction_coef       0.049(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   1.078
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     133
_refine_ls_number_reflns         1066
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.078
_refine_ls_R_factor_all          0.0426
_refine_ls_R_factor_gt           0.0425
_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^)+(0.0719P)^2^+2.386P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1103
_refine_ls_wR_factor_ref         0.1104
_reflns_number_gt                1048
_reflns_number_total             1066
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ac2044.cif
_cod_data_source_block           I
_cod_database_code               2210849
_cod_database_fobs_code          2210849