A Viable Anionic N-Heterocyclic Dicarbene
Yuzhong Wang; Yaoming Xie; Mariham Y. Abraham; Pingrong Wei; Henry F. Schaefer; Paul v. R. Schleyer; Gregory H. Robinson; Journal of the American Chemical Society 132 (2010) 14370–14372; doi:10.1021/ja106631r

data_4103312
_publ_section_title
;
 A Viable Anionic N-Heterocyclic Dicarbene
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              14370
_journal_page_last               14372
_journal_paper_doi               10.1021/ja106631r
_journal_volume                  132
_journal_year                    2010
_chemical_formula_sum            'C46 H74 B Li N4'
_chemical_formula_weight         700.84
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   13.430(2)
_cell_length_b                   20.533(3)
_cell_length_c                   34.121(5)
_cell_measurement_reflns_used    5761
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      19.346
_cell_measurement_theta_min      2.170
_cell_volume                     9409(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'BRUKER APEX II'
_diffrn_measurement_method       'OMEGA SCAN'
_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  0.2000
_diffrn_reflns_av_sigmaI/netI    0.0841
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            99697
_diffrn_reflns_theta_full        25.40
_diffrn_reflns_theta_max         25.40
_diffrn_reflns_theta_min         2.07
_exptl_absorpt_coefficient_mu    0.056
_exptl_absorpt_correction_T_max  0.9978
_exptl_absorpt_correction_T_min  0.9855
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'BRUKER SADABS'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    0.989
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             3088
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.150
_refine_diff_density_min         -0.151
_refine_diff_density_rms         0.029
_refine_ls_extinction_coef       0.0012(2)
_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   1.001
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     582
_refine_ls_number_reflns         8644
_refine_ls_number_restraints     180
_refine_ls_restrained_S_all      1.009
_refine_ls_R_factor_all          0.2127
_refine_ls_R_factor_gt           0.0703
_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^)+(0.0787P)^2^+0.7339P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1504
_refine_ls_wR_factor_ref         0.2086
_reflns_number_gt                3121
_reflns_number_total             8644
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja106631r_si_005.cif
_cod_data_source_block           j2
_cod_original_cell_volume        9409(3)
_cod_database_code               4103312