Planar, Twisted, and Trans-Bent: Conformational Flexibility of Neutral Diborenes
Yuzhong Wang; Brandon Quillian; Pingrong Wei; Yaoming Xie; Chaitanya S. Wannere; R. Bruce King; Henry F. Schaefer; Paul V. R. Schleyer; Gregory H. Robinson; Journal of the American Chemical Society 130 (2008) 3298–3299; doi:10.1021/ja800257j

data_4107574
_publ_section_title
;
 Planar, Twisted, and Trans-Bent: Conformational Flexibility of Neutral
 Diborenes
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              3298
_journal_page_last               3299
_journal_paper_doi               10.1021/ja800257j
_journal_volume                  130
_journal_year                    2008
_chemical_formula_sum            'C42 H52 B2 N4'
_chemical_formula_weight         634.50
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 102.2200(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   32.1297(19)
_cell_length_b                   10.7328(6)
_cell_length_c                   23.9977(15)
_cell_measurement_temperature    273(2)
_cell_volume                     8087.9(8)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0718
_diffrn_reflns_av_sigmaI/netI    0.0491
_diffrn_reflns_limit_h_max       38
_diffrn_reflns_limit_h_min       -38
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            42273
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    0.060
_exptl_absorpt_correction_T_max  0.9970
_exptl_absorpt_correction_T_min  0.9822
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'BRUKER SADABS'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.042
_exptl_crystal_F_000             2736
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.271
_refine_diff_density_min         -0.237
_refine_diff_density_rms         0.048
_refine_ls_extinction_coef       0.00054(14)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     450
_refine_ls_number_reflns         7130
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.1270
_refine_ls_R_factor_gt           0.0607
_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^)+(0.0832P)^2^+7.5622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1527
_refine_ls_wR_factor_ref         0.1999
_reflns_number_gt                3736
_reflns_number_total             7130
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja800257j-file005.cif
_cod_data_source_block           uga632
_cod_database_code               4107574