<i>rac</i>-7-Methyl-3-[(7-methyl-4-oxochroman-3-yl)methyl]-4<i>H</i>-chromen-4-one
Somasundaram, M.; Rajendiran, A.; Balasubramanian, K.K.; Krishnasamy, K.; Kabilan, S.; Acta Crystallographica Section E 69 (2013) o763–; doi:10.1107/S1600536813009422

data_2238119
_publ_section_title
;
 <i>rac</i>-7-Methyl-3-[(7-methyl-4-oxochroman-3-yl)methyl]-4<i>H</i>-chromen-4-one
;
_journal_coeditor_code           ZS2250
_journal_issue                   5
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o763
_journal_paper_doi               10.1107/S1600536813009422
_journal_volume                  69
_journal_year                    2013
_chemical_formula_iupac          'C21 H18 O4'
_chemical_formula_moiety         'C21 H18 O4'
_chemical_formula_sum            'C21 H18 O4'
_chemical_formula_weight         334.35
_chemical_name_systematic
<i>rac</i>-7-Methyl-3-[(7-methyl-4-oxochroman-3-yl)methyl]-4<i>H</i>-chromen-4-one
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 91.11(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.664(2)
_cell_length_b                   6.6428(13)
_cell_length_c                   23.754(5)
_cell_measurement_reflns_used    2970
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.17
_cell_measurement_theta_min      2.49
_cell_volume                     1682.4(6)
_computing_cell_refinement       'SAINT (Bruker, 2007)'
_computing_data_collection       'SMART (Bruker, 2007)'
_computing_data_reduction        'SAINT (Bruker, 2007)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.966
_diffrn_measured_fraction_theta_max 0.966
_diffrn_measurement_device_type  'Bruker SMART CCD'
_diffrn_measurement_method       '\f and \w scans'
_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  0.0290
_diffrn_reflns_av_sigmaI/netI    0.0484
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            11780
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         3.18
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.9803
_exptl_absorpt_correction_T_min  0.9611
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2007)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.320
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       crystal
_exptl_crystal_F_000             704
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.429
_refine_diff_density_min         -0.298
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     229
_refine_ls_number_reflns         4032
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.020
_refine_ls_R_factor_all          0.1324
_refine_ls_R_factor_gt           0.0586
_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^)+(0.0748P)^2^+0.4282P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1433
_refine_ls_wR_factor_ref         0.1798
_reflns_number_gt                1982
_reflns_number_total             4032
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            zs2250.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               2238119
_cod_database_fobs_code          2238119