π-Stacked dimers in 6-methoxy-3,3-dimethyl-3<i>H</i>-benzo[<i>f</i>]chromene, and centrosymmetric dimers containing C—H···π(arene) hydrogen bonds in racemic 3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2<i>H</i>,6<i>H</i>-1,5-dioxatriphenylene
Silva, Fernando de C. da; Wardell, James L.; Wardell, Solange M. S. V.; Ferreira, Vitor F.; Low, John N.; Glidewell, Christopher; Acta Crystallographica Section C 63 (2007) o568–o571; doi:10.1107/S0108270107039194

data_2016199
_publ_section_title
;\p-Stacked dimers in
 6-methoxy-3,3-dimethyl-3<i>H</i>-benzo[<i>f</i>]chromene, and centrosymmetric
 dimers containing C---H&#x00B7;&#x00B7;&#x00B7;\p(arene) hydrogen bonds in
 racemic
 3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2<i>H</i>,6<i>H</i>-1,5-dioxatriphenylene
;
_journal_coeditor_code           GG3118
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o568
_journal_page_last               o571
_journal_paper_doi               10.1107/S0108270107039194
_journal_volume                  63
_journal_year                    2007
_chemical_formula_iupac          'C20 H21 Br O2'
_chemical_formula_moiety         'C20 H21 Br O2'
_chemical_formula_sum            'C20 H21 Br O2'
_chemical_formula_weight         373.28
_chemical_name_systematic
;
rac-3-bromo-2,2,6,6-tetramethyl-3,4-dihydro-2H,6H-1,5-dioxatriphenylene
;
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 106.3430(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.7350(2)
_cell_length_b                   13.7043(3)
_cell_length_c                   12.0692(2)
_cell_measurement_reflns_used    3910
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.53
_cell_measurement_theta_min      1.98
_cell_volume                     1703.83(6)
_computing_cell_refinement       'DENZO (Otwinowski & Minor, 1997) and COLLECT'
_computing_data_collection       'COLLECT (Nonius, 1999)'
_computing_data_reduction        'DENZO and COLLECT'
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  'SHELXL97 and PRPKAPPA (Ferguson, 1999)'
_computing_structure_refinement  'OSCAIL and SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution
'OSCAIL (McArdle, 2003) and SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean 9.091
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker Nonius KappaCCD area-detector'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Bruker-Nonius FR591 rotating anode'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0352
_diffrn_reflns_av_sigmaI/netI    0.0234
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            27068
_diffrn_reflns_theta_full        27.53
_diffrn_reflns_theta_max         27.53
_diffrn_reflns_theta_min         1.98
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.420
_exptl_absorpt_correction_T_max  0.647
_exptl_absorpt_correction_T_min  0.378
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS;(Sheldrick, 2003)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.455
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.44
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.429
_refine_diff_density_min         -0.491
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.181
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     212
_refine_ls_number_reflns         3910
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.181
_refine_ls_R_factor_all          0.0385
_refine_ls_R_factor_gt           0.0264
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0463P)^2^+0.5898P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0690
_refine_ls_wR_factor_ref         0.0882
_reflns_number_gt                3289
_reflns_number_total             3910
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            gg3118.cif
_cod_data_source_block           IV
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2016199
_cod_database_fobs_code          2016199