Synthesis and characterization of electron-deficient pentacenes.
Swartz, Christopher R.; Parkin, Sean R.; Bullock, Joseph E.; Anthony, John E.; Mayer, Alex C.; Malliaras, George G.; Organic letters 7 (2005) 3163–3166; doi:10.1021/ol050872b

data_1506600
_publ_section_title
;
 Synthesis and characterization of electron-deficient pentacenes.
;
_journal_issue                   15
_journal_name_full               'Organic letters'
_journal_page_first              3163
_journal_page_last               3166
_journal_paper_doi               10.1021/ol050872b
_journal_volume                  7
_journal_year                    2005
_chemical_formula_moiety         'C44 H50 Br4 Si2'
_chemical_formula_sum            'C44 H50 Br4 Si2'
_chemical_formula_weight         954.62
_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                 105.8240(8)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.6750(2)
_cell_length_b                   17.6320(4)
_cell_length_c                   14.6570(3)
_cell_measurement_reflns_used    5108
_cell_measurement_temperature    90.0(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      1.00
_cell_volume                     2156.94(8)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'XP in Siemens SHELXTL (Sheldrick, 1994)'
_computing_publication_material
;
SHELX97-2 (Sheldrick, 1997) and local procedures
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      90.0(2)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       '\w scans at fixed \c = 55\%'
_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  0.0583
_diffrn_reflns_av_sigmaI/netI    0.0790
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            7474
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         1.85
_diffrn_standards_decay_%        <1
_exptl_absorpt_coefficient_mu    3.816
_exptl_absorpt_correction_T_max  0.8941
_exptl_absorpt_correction_T_min  0.5982
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Scalepack (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            'very dark blue'
_exptl_crystal_density_diffrn    1.470
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             964
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.03
_refine_diff_density_max         1.436
_refine_diff_density_min         -0.446
_refine_diff_density_rms         0.118
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     232
_refine_ls_number_reflns         3806
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.1068
_refine_ls_R_factor_gt           0.0575
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0852P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1342
_refine_ls_wR_factor_ref         0.1533
_reflns_number_gt                2420
_reflns_number_total             3802
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol050872bsi20050609_051818.cif
_cod_data_source_block           k03140
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1506600