Synthesis, structure, and properties of benzoquinone dimer and trimers bearing t-Bu substituents.
Hayashi, Naoto; Yoshikawa, Takahiro; Ohnuma, Takahiro; Higuchi, Hiroyuki; Sako, Katsuya; Uekusa, Hidehiro; Organic letters 9 (2007) 5417–5420; doi:10.1021/ol702289u

data_1505621
_publ_section_title
;
 Synthesis, structure, and properties of benzoquinone dimer and trimers
 bearing t-Bu substituents.
;
_journal_issue                   26
_journal_name_full               'Organic letters'
_journal_page_first              5417
_journal_page_last               5420
_journal_paper_doi               10.1021/ol702289u
_journal_volume                  9
_journal_year                    2007
_chemical_formula_sum            'C20 H22 O4'
_chemical_formula_weight         326.39
_chemical_name_systematic
; 
 5,5'-di-tert-butyl-2,2'-bis-p-benzoquinone
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                 94.84(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   10.392(2)
_cell_length_b                   6.462(2)
_cell_length_c                   13.048(2)
_cell_measurement_reflns_used    20
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      12.5
_cell_measurement_theta_min      10
_cell_volume                     873.1(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'RIGAKU AFC-5S'
_diffrn_measurement_method       w/2q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0418
_diffrn_reflns_av_sigmaI/netI    0.0095
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            1462
_diffrn_reflns_theta_full        30.02
_diffrn_reflns_theta_max         30.02
_diffrn_reflns_theta_min         3.13
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 200
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            'brownish orange'
_exptl_crystal_density_diffrn    1.203
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             336
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.60
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.276
_refine_diff_density_min         -0.196
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.3(18)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     153
_refine_ls_number_reflns         1390
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0513
_refine_ls_R_factor_gt           0.0448
_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^)+(0.1013P)^2^+0.2286P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1268
_refine_ls_wR_factor_ref         0.1411
_reflns_number_gt                1283
_reflns_number_total             1390
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol702289u-file003.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      C2
_cod_database_code               1505621