A new route to dilithio boraamidinates: formation and X-ray structures of the dimeric and trimeric clusters {Li2[RB(NBut)2]}x (R = Bun, x = 2 and R = Me, x = 3)
Brask, Justin K.; Chivers, Tristram; Schatte, Gabriele; Chemical Communications  (2000) 1805–; doi:10.1039/b005852l

data_7111073
_publ_section_title
;
 A new route to dilithio boraamidinates: formation and X-ray structures of
 the dimeric and trimeric clusters {Li2[RB(NBut)2]}x (R = Bun, x = 2 and R
 = Me, x = 3)
;
_journal_issue                   18
_journal_name_full               'Chemical Communications'
_journal_page_first              1805
_journal_paper_doi               10.1039/b005852l
_journal_year                    2000
_chemical_formula_moiety         'C27 H63 B3 Li6 N6'
_chemical_formula_sum            'C27 H63 B3 Li6 N6'
_chemical_formula_weight         545.90
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 116.0730(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.3587(13)
_cell_length_b                   12.0750(8)
_cell_length_c                   19.2718(14)
_cell_measurement_reflns_used    2842
_cell_measurement_temperature    193(2)
_cell_volume                     3628.4(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'ORTEP-3 (1.06) in WinGX-1.62'
_computing_publication_material  WinGX-1.63
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      193(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0388
_diffrn_reflns_av_sigmaI/netI    0.0286
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            10572
_diffrn_reflns_theta_full        24.71
_diffrn_reflns_theta_max         24.71
_diffrn_reflns_theta_min         2.13
_diffrn_standards_decay_%        'no decay'
_exptl_absorpt_coefficient_mu    0.055
_exptl_absorpt_correction_T_max  0.9836
_exptl_absorpt_correction_T_min  0.9809
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
; SADABS, V 2.01, Software for Area-Detector Absorption
  Corrections; Bruker AXS Inc., Madison, WI, 2000.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    0.999
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1200
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.473
_refine_diff_density_min         -0.199
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     202
_refine_ls_number_reflns         3104
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0842
_refine_ls_R_factor_gt           0.0611
_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^)+(0.0917P)^2^+2.9893P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1617
_refine_ls_wR_factor_ref         0.1775
_reflns_number_gt                2302
_reflns_number_total             3104
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b005852lsup1.cif
_cod_data_source_block           4a
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               7111073