Iron-Amide-Sulfide and Iron-Imide-Sulfide Clusters: Heteroligated Core Environments Relevant to the Nitrogenase FeMo Cofactor
Xu-Dong Chen; Wei Zhang; Jeremiah S. Duncan; Sonny C. Lee; Inorganic Chemistry 51 (2012) 12891–12904; doi:10.1021/ic301868m

data_4331180
_publ_contact_author_address
;                                                                               
 Department of Chemistry
 University of Waterloo
 200 University Avenue West
 Waterloo, Ontario  N2L 3G1
 CANADA  
;
_publ_contact_author_email       sclee@uwaterloo.ca
_publ_contact_author_fax         519-746-0435
_publ_contact_author_name        'Sonny C. Lee'
_publ_contact_author_phone       '519-885-1211 x37501'
_publ_section_title
;
 Iron-Amide-Sulfide and Iron-Imide-Sulfide Clusters: Heteroligated Core
 Environments Relevant to the Nitrogenase FeMo Cofactor
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              12891
_journal_page_last               12904
_journal_paper_doi               10.1021/ic301868m
_journal_volume                  51
_journal_year                    2012
_chemical_formula_moiety
'(Et4N +)2 [ (Fe 3+)2 (Fe 2+)2 (NtBu 2-) (Se 2-)3 (Cl -)4 ]'
_chemical_formula_sum            'C20 H49 Cl4 Fe4 N3 Se3'
_chemical_formula_weight         933.70
_chemical_name_common            (Et4N)2[Fe4(mu3-NtBu)(mu3-Se)3Cl4]
_chemical_name_systematic
; 
 (Et4N)2[Fe4(mu3-NtBu)(mu3-Se)3Cl4] 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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            4
_cell_length_a                   11.5384(12)
_cell_length_b                   14.1705(15)
_cell_length_c                   21.395(2)
_cell_measurement_reflns_used    4700
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      21.15
_cell_measurement_theta_min      2.87
_cell_volume                     3498.2(6)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0650
_diffrn_reflns_av_sigmaI/netI    0.0552
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            27688
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.87
_exptl_absorpt_coefficient_mu    5.068
_exptl_absorpt_correction_T_max  0.8230
_exptl_absorpt_correction_T_min  0.4019
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   APEXII
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.773
_exptl_crystal_description       block
_exptl_crystal_F_000             1856
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.476
_refine_diff_density_min         -0.328
_refine_diff_density_rms         0.083
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.012(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.986
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     307
_refine_ls_number_reflns         6156
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.986
_refine_ls_R_factor_all          0.0462
_refine_ls_R_factor_gt           0.0336
_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^)+(0.0300P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0686
_refine_ls_wR_factor_ref         0.0752
_reflns_number_gt                5219
_reflns_number_total             6156
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic301868m_si_002_8.cif
_cod_data_source_block           sl42
_cod_original_cell_volume        3498.3(6)
_cod_database_code               4331180