N-Heterocyclic Carbene Boryl Radicals: A New Class of Boron-Centered Radical
Shau-Hua Ueng; Andrey Solovyev; Xinting Yuan; Steven J. Geib; Louis Fensterbank; Emmanuel Lacôte; Max Malacria; Martin Newcomb; John C. Walton; Dennis P. Curran; Journal of the American Chemical Society 131 (2009) 11256–11262; doi:10.1021/ja904103x

data_4104846
_publ_section_title
;
 N-Heterocyclic Carbene Boryl Radicals: A New Class of Boron-Centered
 Radical
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              11256
_journal_page_last               11262
_journal_paper_doi               10.1021/ja904103x
_journal_volume                  131
_journal_year                    2009
_chemical_formula_moiety         'C41 H57 B N2 O2 S2'
_chemical_formula_sum            'C41 H57 B N2 O2 S2'
_chemical_formula_weight         684.82
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 90.754(9)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.1188(19)
_cell_length_b                   14.337(2)
_cell_length_c                   20.757(2)
_cell_measurement_reflns_used    129
_cell_measurement_temperature    250(2)
_cell_measurement_theta_max      18.3
_cell_measurement_theta_min      3.9
_cell_volume                     4201.3(9)
_computing_cell_refinement       'Dirax/lsq (Duisenberg & Schreurs, 1989-2000)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction        'EvalCCD (Duisenberg & Schreurs 1990-2000)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1999)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1993)'
_diffrn_ambient_temperature      250(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'CCD rotation images, thick slices'
_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  0.0667
_diffrn_reflns_av_sigmaI/netI    0.0785
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            44254
_diffrn_reflns_theta_full        27.51
_diffrn_reflns_theta_max         27.51
_diffrn_reflns_theta_min         2.26
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.160
_exptl_absorpt_correction_T_max  0.979
_exptl_absorpt_correction_T_min  0.764
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
R.H. Blessing, Acta Cryst. (1995), A51, 33-38
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.083
_exptl_crystal_description       block
_exptl_crystal_F_000             1480
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.611
_refine_diff_density_min         -0.697
_refine_diff_density_rms         0.047
_refine_ls_extinction_coef       0.0037(10)
_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   1.019
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     451
_refine_ls_number_reflns         9613
_refine_ls_number_restraints     8
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.1788
_refine_ls_R_factor_gt           0.0702
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0868P)^2^+2.6458P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1694
_refine_ls_wR_factor_ref         0.2268
_reflns_number_gt                4233
_reflns_number_total             9613
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja904103x_si_003.cif
_cod_data_source_block           shu1036b
_cod_original_cell_volume        4201.3(10)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4104846