Conformations of imperatorin
Atta-ur-Rahman; Zareen, Seema; Choudhary, M. Iqbal; Shaheen, Farzana; Parvez, Masood; Acta Crystallographica Section E 60 (2004) o1460–o1462; doi:10.1107/S1600536804018604

data_2204195
_publ_section_title
;
 Conformations of imperatorin
;
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1460
_journal_page_last               o1462
_journal_paper_doi               10.1107/S1600536804018604
_journal_volume                  60
_journal_year                    2004
_chemical_formula_iupac          'C16 H14 O4'
_chemical_formula_moiety         'C16 H14 O4'
_chemical_formula_sum            'C16 H14 O4'
_chemical_formula_weight         270.27
_chemical_name_common
;
Imperatorin
;
_chemical_name_systematic
;
9-(3-methylbut-2-enyloxy)-7H-furo[3,2-g]chromen-7-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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                64.72(4)
_cell_angle_beta                 89.47(3)
_cell_angle_gamma                84.17(2)
_cell_formula_units_Z            4
_cell_length_a                   11.041(6)
_cell_length_b                   11.729(6)
_cell_length_c                   11.800(7)
_cell_measurement_reflns_used    14651
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      30.0
_cell_measurement_theta_min      2.9
_cell_volume                     1373.6(14)
_computing_cell_refinement       'HKL DENZO (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Hooft, 1998)'
_computing_data_reduction        'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'ORTEPII (Johnson, 1976)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SAPI91 (Fan, 1991)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.977
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\w and \f'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.019
_diffrn_reflns_av_sigmaI/netI    0.034
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            14651
_diffrn_reflns_theta_full        30.0
_diffrn_reflns_theta_max         30.0
_diffrn_reflns_theta_min         2.9
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.307
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       block
_exptl_crystal_F_000             568
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.36
_refine_diff_density_min         -0.32
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.00
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     361
_refine_ls_number_reflns         7853
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.00
_refine_ls_R_factor_all          0.062
_refine_ls_R_factor_gt           0.048
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.00
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.075P)^2^+0.4P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.131
_refine_ls_wR_factor_ref         0.142
_reflns_number_gt                6297
_reflns_number_total             7853
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lh6250.cif
_cod_data_source_block           I
_cod_original_cell_volume        1373.6(13)
_cod_database_code               2204195
_cod_database_fobs_code          2204195