Synthesis, crystal structure, and physical properties of 7,14-disubstituted pentacene-5,12-diones containing a methylenequinoid structure.
Nishida, Jun-Ichi; Fujiwara, Yujiro; Yamashita, Yoshiro; Organic letters 11 (2009) 1813–1816; doi:10.1021/ol9003838

data_1503861
_publ_section_title
;
 Synthesis, crystal structure, and physical properties of
 7,14-disubstituted pentacene-5,12-diones containing a methylenequinoid
 structure.
;
_journal_issue                   8
_journal_name_full               'Organic letters'
_journal_page_first              1813
_journal_page_last               1816
_journal_paper_doi               10.1021/ol9003838
_journal_volume                  11
_journal_year                    2009
_chemical_formula_moiety         'C44 H52 O2 Si2 '
_chemical_formula_sum            'C44 H52 O2 Si2'
_chemical_formula_weight         669.06
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_cell_angle_alpha                90.0000
_cell_angle_beta                 105.4951(18)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            4
_cell_length_a                   14.2666(7)
_cell_length_b                   11.6671(6)
_cell_length_c                   23.4260(14)
_cell_measurement_reflns_used    16991
_cell_measurement_temperature    93.1
_cell_measurement_theta_max      25.4
_cell_measurement_theta_min      3.0
_cell_volume                     3757.5(4)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       PROCESS-AUTO
_computing_data_reduction        CrystalStructure
_computing_publication_material  'CrystalStructure 3.8'
_computing_structure_refinement  SHELXL
_computing_structure_solution    SIR97
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Rigaku RAXIS-RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.069
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            29166
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_exptl_absorpt_coefficient_mu    0.130
_exptl_absorpt_correction_T_max  0.987
_exptl_absorpt_correction_T_min  0.752
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
    Higashi, T. (1995). Program for Absorption Correction.
    Rigaku Corporation, Tokyo, Japan.
;
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.183
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1440.00
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.53
_refine_diff_density_min         -0.43
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.988
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     446
_refine_ls_number_reflns         6862
_refine_ls_R_factor_gt           0.0587
_refine_ls_shift/su_max          0.0010
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0951P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1629
_reflns_number_gt                4579
_reflns_number_total             6862
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            ol9003838_si_001.cif
_cod_data_source_block           '_comp2'
_cod_original_cell_volume        3757.5(3)
_cod_original_formula_sum        'C44 H52 O2 Si2 '
_cod_database_code               1503861