2',6'-Dihydroxyflavone and a New Polymorph of 2'-Hydroxyflavonol
Molins, E.; Miravitlles, C.; Wallet, J.-C.; Gaydou, E. M.; Acta Crystallographica Section C 52 (1996) 925–929; doi:10.1107/S0108270195013679

data_2004804
_publ_section_title
;
 2',6'-Dihydroxyflavone and a New Polymorph of 2'-Hydroxyflavonol
;
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              925
_journal_page_last               929
_journal_paper_doi               10.1107/S0108270195013679
_journal_volume                  52
_journal_year                    1996
_chemical_formula_sum            'C15 H10 O4'
_chemical_formula_weight         254.24
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_type_scat_source           IntTabIV
_cell_angle_alpha                90
_cell_angle_beta                 102.15(1)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   18.285(2)
_cell_length_b                   7.726(1)
_cell_length_c                   16.927(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293
_cell_measurement_theta_max      20
_cell_measurement_theta_min      16
_cell_volume                     2337.7(5)
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_method       \w-2\q
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0135
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       0
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            3640
_diffrn_reflns_theta_max         30.4
_diffrn_standards_decay_%        0.4
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.106
_exptl_absorpt_correction_T_max  0.999
_exptl_absorpt_correction_T_min  0.945
_exptl_absorpt_correction_type   'empirical via \y scan (MolEN; Fair, 1990)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.445
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_size_max          0.58
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.286
_refine_diff_density_min         -0.187
_refine_ls_extinction_coef       0.0046(9)
_refine_ls_extinction_method     empirical
_refine_ls_goodness_of_fit_obs   0.786
_refine_ls_hydrogen_treatment    refU
_refine_ls_number_parameters     204
_refine_ls_number_reflns         3529
_refine_ls_R_factor_obs          0.0424
_refine_ls_shift/esd_max         0.04
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_scheme
;
w = 1/[\s^2^(F~o~)^2^ + (0.0715P)^2^ + 0.7135P]
where P = [max(0,F~o~^2^) + 2F~c~^2^]/3
;
_refine_ls_wR_factor_obs         0.1290
_reflns_number_observed          2268
_reflns_number_total             3529
_reflns_observed_criterion       I>2\s(I)
_cod_data_source_file            pa1197.cif
_cod_data_source_block           1
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               2004804