4,7,8-Trimethyl-2<i>H</i>-chromen-2-one
Yang, Jian-Xin; Tan, Xue-Mei; Wang, Xiang-Hui; Wang, Yin; Acta Crystallographica Section E 68 (2012) o1014–; doi:10.1107/S1600536812009646

data_2234310
_publ_section_title
;
 4,7,8-Trimethyl-2<i>H</i>-chromen-2-one
;
_journal_coeditor_code           LD2048
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o1014
_journal_paper_doi               10.1107/S1600536812009646
_journal_volume                  68
_journal_year                    2012
_chemical_formula_iupac          'C12 H12 O2'
_chemical_formula_sum            'C12 H12 O2'
_chemical_formula_weight         188.22
_chemical_name_systematic
;
4,7,8-Trimethyl-2<i>H</i>-chromen-2-one
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 97.055(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.276(3)
_cell_length_b                   18.075(6)
_cell_length_c                   7.246(3)
_cell_measurement_reflns_used    3283
_cell_measurement_temperature    153(2)
_cell_measurement_theta_max      30.033
_cell_measurement_theta_min      2.254
_cell_volume                     945.7(6)
_computing_cell_refinement       'CrystalClear (Rigaku, 2008)'
_computing_data_collection       'CrystalClear (Rigaku, 2008)'
_computing_data_reduction        'CrystalClear (Rigaku, 2008)'
_computing_molecular_graphics
'SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov <i>et al.</i>, 2009)'
_computing_publication_material
'SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      153(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Rigaku AFC10/Saturn724+'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0284
_diffrn_reflns_av_sigmaI/netI    0.0307
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            8545
_diffrn_reflns_theta_full        30.06
_diffrn_reflns_theta_max         30.06
_diffrn_reflns_theta_min         3.05
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.322
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Prism
_exptl_crystal_F_000             400
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.31
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.283
_refine_diff_density_min         -0.325
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     130
_refine_ls_number_reflns         2747
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.000
_refine_ls_R_factor_all          0.0679
_refine_ls_R_factor_gt           0.0502
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0269P)^2^+0.5510P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1031
_refine_ls_wR_factor_ref         0.1117
_reflns_number_gt                2176
_reflns_number_total             2747
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            ld2048.cif
_cod_data_source_block           I
_cod_original_cell_volume        945.8(6)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               2234310
_cod_database_fobs_code          2234310