Synthesis of bent [4]phenylene (cyclobuta[1,2-a:3,4-b′]bisbiphenylene) and structure of a bis(trimethylsilyl) derivative: the last [4]phenylene isomerElectronic supplementary information (ESI) available: selected bond distances and angles for 9, spectral and analytical information. See http://www.rsc.org/suppdata/cc/b1/b109789j/
Bong, Dennis T.-Y.; Gentric, Lionel; Holmes, Daniel; Matzger, Adam J.; Scherhag, Frank; Vollhardt, K. Peter C.; Chemical Communications  (2002) 278–; doi:10.1039/b109789j

data_7111187
_publ_section_title
;
 Synthesis of bent [4]phenylene
 (cyclobuta[1,2-a:3,4-b&#x2032;]bisbiphenylene) and structure of a
 bis(trimethylsilyl) derivative: the last [4]phenylene isomerElectronic
 supplementary information (ESI) available: selected bond distances and
 angles for 9, spectral and analytical information. See
 http://www.rsc.org/suppdata/cc/b1/b109789j/
;
_journal_issue                   3
_journal_name_full               'Chemical Communications'
_journal_page_first              278
_journal_paper_doi               10.1039/b109789j
_journal_year                    2002
_chemical_formula_moiety         'C30 H28 Si2 '
_chemical_formula_sum            'C30 H28 Si2'
_chemical_formula_weight         444.72
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_audit_creation_date             'Tue Sep  4 13:59:14 2001'
_audit_creation_method           'by teXsan'
_cell_angle_alpha                90
_cell_angle_beta                 103.155(1)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.5453(2)
_cell_length_b                   22.1287(3)
_cell_length_c                   12.05250(10)
_cell_measurement_reflns_used    8192
_cell_measurement_temperature    147.2
_cell_measurement_theta_max      45.0
_cell_measurement_theta_min      3.5
_cell_volume                     2478.98(7)
_computing_cell_refinement       'Bruker SAINT v5.04'
_computing_data_collection       'Bruker SMART v5.052d'
_computing_data_reduction        'Bruker SAINT v5.04'
_computing_publication_material  teXsan
_computing_structure_refinement  teXsan
_diffrn_ambient_temperature      147.2
_diffrn_measurement_device_type  'SMART CCD'
_diffrn_measurement_method       \w-scan
_diffrn_orient_matrix_UB_11      0.00000
_diffrn_orient_matrix_UB_12      0.00000
_diffrn_orient_matrix_UB_13      0.00000
_diffrn_orient_matrix_UB_21      0.00000
_diffrn_orient_matrix_UB_22      0.00000
_diffrn_orient_matrix_UB_23      0.00000
_diffrn_orient_matrix_UB_31      0.00000
_diffrn_orient_matrix_UB_32      0.00000
_diffrn_orient_matrix_UB_33      0.00000
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.027
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            10629
_diffrn_reflns_theta_max         25.65
_diffrn_reflns_theta_min         1.7
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.158
_exptl_absorpt_correction_T_max  1.00
_exptl_absorpt_correction_T_min  1.00
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   'Bruker, 1995'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.191
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             944.00
_exptl_crystal_size_max          0.300
_exptl_crystal_size_mid          0.250
_exptl_crystal_size_min          0.150
_refine_diff_density_max         0.17
_refine_diff_density_min         -0.25
_refine_ls_extinction_coef       4.53893
_refine_ls_extinction_method     Zachariasen_type_2_Gaussian_isotropic
_refine_ls_goodness_of_fit_ref   2.054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     576
_refine_ls_number_reflns         7219
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0397
_refine_ls_R_factor_gt           0.0360
_refine_ls_shift/su_max          0.0090
_refine_ls_structure_factor_coef F
_refine_ls_weighting_scheme      sigma
_refine_ls_wR_factor_all         0.0508
_refine_ls_wR_factor_gt          0.0497
_refine_ls_wR_factor_ref         0.0497
_reflns_number_gt                7219
_reflns_number_total             7710
_reflns_threshold_expression     I>3.00sigma
_cod_data_source_file            b109789jsup1.cif
_cod_data_source_block           bent4_reconstruction
_cod_original_cell_volume        2478.98(6)
_cod_original_sg_symbol_H-M      'P 21       '
_cod_original_formula_sum        'C30 H28 Si2 '
_cod_database_code               7111187