A second triclinic modification of 2',6'-dimethoxyflavone
Wallet, J.-C.; Molins, Elies; Miravitlles, Carlos; Acta Crystallographica Section C 56 (2000) e414–e414; doi:10.1107/S0108270100011008

data_2011360
_publ_section_title
;
 A second triclinic modification of 2',6'-dimethoxyflavone
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              e414
_journal_page_last               e414
_journal_paper_doi               10.1107/S0108270100011008
_journal_volume                  56
_journal_year                    2000
_chemical_formula_moiety         'C17 H14 O4'
_chemical_formula_structural     'C17 H14 O4'
_chemical_formula_sum            'C17 H14 O4'
_chemical_formula_weight         282.28
_chemical_name_systematic        2-(2,6-dimethoxyphenyl)-4H-1-benzopyran-4-one
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.1beta3
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                97.57(4)
_cell_angle_beta                 105.69(3)
_cell_angle_gamma                103.60(3)
_cell_formula_units_Z            2
_cell_length_a                   7.721(2)
_cell_length_b                   8.905(5)
_cell_length_c                   11.231(4)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.89
_cell_measurement_theta_min      2.41
_cell_volume                     706.7(5)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection       'CAD-4 EXPRESS (Enraf-Nonius, 1994)'
_computing_data_reduction        'XCAD-4 (Harms & Wocadlo, 1995)'
_computing_publication_material  'WinGX (Farrugia, 1998)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full .974
_diffrn_measured_fraction_theta_max .974
_diffrn_measurement_device       '\k-geometry diffractometer'
_diffrn_measurement_device_type  'Enraf-Nonius CAD-4'
_diffrn_measurement_method       'non-profiled \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     .71073
_diffrn_reflns_av_R_equivalents  .05
_diffrn_reflns_av_sigmaI/netI    .1116
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4215
_diffrn_reflns_theta_full        29.99
_diffrn_reflns_theta_max         29.99
_diffrn_reflns_theta_min         2.41
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 76
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    .095
_exptl_absorpt_correction_T_max  .979
_exptl_absorpt_correction_T_min  .907
_exptl_absorpt_correction_type   '\y scan'
_exptl_absorpt_process_details   '(North et al., 1968)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.327
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             296
_exptl_crystal_size_max          .42
_exptl_crystal_size_mid          .40
_exptl_crystal_size_min          .05
_refine_diff_density_max         .133
_refine_diff_density_min         -.161
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   .917
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         4021
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      .917
_refine_ls_R_factor_all          .203
_refine_ls_R_factor_gt           .055
_refine_ls_shift/su_max          .004
_refine_ls_shift/su_mean         .001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
w = 1/[(\s^2^(F~o~^2^)+(0.0566P)^2^] where P = [2F~c~^2^+max(F~o~^2^,0)]/3
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .143
_reflns_number_gt                1476
_reflns_number_total             4021
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            qd0002.cif
_cod_data_source_block           I
_cod_database_code               2011360