Dodecamethoxy- and hexaoxotricyclobutabenzene: synthesis and characterization.
Hamura, Toshiyuki; Ibusuki, Yousuke; Uekusa, Hidehiro; Matsumoto, Takashi; Siegel, Jay S; Baldridge, Kim K; Suzuki, Keisuke; Journal of the American Chemical Society 128 (2006) 10032–10033; doi:10.1021/ja064063e

data_4101565
_publ_section_title
;
 Dodecamethoxy- and hexaoxotricyclobutabenzene: synthesis and
 characterization.
;
_journal_issue                   31
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10032
_journal_page_last               10033
_journal_paper_doi               10.1021/ja064063e
_journal_volume                  128
_journal_year                    2006
_chemical_formula_moiety         'C24 H36 O12'
_chemical_formula_sum            'C24 H36 O12'
_chemical_formula_weight         516.53
_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                 115.171(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.3650(13)
_cell_length_b                   10.4112(7)
_cell_length_c                   22.0747(16)
_cell_measurement_reflns_used    36250
_cell_measurement_temperature    93(2)
_cell_volume                     2571.9(4)
_computing_cell_refinement       Denzo
_computing_data_collection       'Rigaku RAPID AUTO'
_computing_data_reduction        Denzo
_computing_molecular_graphics    'ORTEP-3 for Windows (Farrugia, 1998)'
_computing_publication_material  SHELXL-97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      93(2)
_diffrn_detector_area_resol_mean 10
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w-scans
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode Rigaku UX-18'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0426
_diffrn_reflns_av_sigmaI/netI    0.0205
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            45417
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         1.82
_exptl_absorpt_coefficient_mu    0.107
_exptl_absorpt_correction_T_max  0.9915
_exptl_absorpt_correction_T_min  0.9604
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Absorption was corrected by SCALEPACK'
_exptl_crystal_colour            transparent
_exptl_crystal_density_diffrn    1.334
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.385
_refine_diff_density_min         -0.207
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     373
_refine_ls_number_reflns         5897
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0570
_refine_ls_R_factor_gt           0.0472
_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^)+(0.0523P)^2^+1.3932P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1170
_refine_ls_wR_factor_ref         0.1218
_reflns_number_gt                4999
_reflns_number_total             5897
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja064063esi20060609_054313.cif
_cod_data_source_block           new
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4101565