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_4107572
_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 H50 B2 N4'
_chemical_formula_weight         632.48
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                87.7140(10)
_cell_angle_beta                 85.2180(10)
_cell_angle_gamma                84.1790(10)
_cell_formula_units_Z            2
_cell_length_a                   8.5126(6)
_cell_length_b                   13.0601(9)
_cell_length_c                   17.4722(12)
_cell_measurement_reflns_used    4843
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      23.717
_cell_measurement_theta_min      2.597
_cell_volume                     1924.8(2)
_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  0.0321
_diffrn_reflns_av_sigmaI/netI    0.0345
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            20729
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.34
_exptl_absorpt_coefficient_mu    0.063
_exptl_absorpt_correction_T_max  0.9906
_exptl_absorpt_correction_T_min  0.9722
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'BRUKER SADABS'
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.091
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.418
_refine_diff_density_min         -0.272
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.014
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     441
_refine_ls_number_reflns         6789
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.014
_refine_ls_R_factor_all          0.0962
_refine_ls_R_factor_gt           0.0631
_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^)+(0.1010P)^2^+1.1333P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1782
_refine_ls_wR_factor_ref         0.2075
_reflns_number_gt                4454
_reflns_number_total             6789
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja800257j-file003.cif
_cod_data_source_block           uga702
_cod_database_code               4107572