A Nitrogenase Cluster Model [Fe8S6O] with an Oxygen Unsymmetrically Bridging Two Proto-Fe4S3 Cubes: Relevancy to the Substrate Binding Mode of the FeMo Cofactor
Shun Ohta; Yasuhiro Ohki; Takayoshi Hashimoto; Roger E. Cramer; Kazuyuki Tatsumi; Inorganic Chemistry 51 (2012) 11217–11219; doi:10.1021/ic301348f

data_4330836
_publ_section_title
;
 A Nitrogenase Cluster Model [Fe8S6O] with an Oxygen Unsymmetrically
 Bridging Two Proto-Fe4S3 Cubes: Relevancy to the Substrate Binding Mode
 of the FeMo Cofactor
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              11217
_journal_page_last               11219
_journal_paper_doi               10.1021/ic301348f
_journal_volume                  51
_journal_year                    2012
_chemical_formula_moiety         'C137 H141 Fe8 O2.45 S10'
_chemical_formula_sum            'C137 H141 Fe8 O2.45 S10'
_chemical_formula_weight         2594.20
_space_group_IT_number           136
_symmetry_cell_setting           tetragonal
_symmetry_Int_Tables_number      136
_symmetry_space_group_name_Hall  '-P 4n 2n'
_symmetry_space_group_name_H-M   'P 42/m n m'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.0000
_cell_angle_beta                 90.0000
_cell_angle_gamma                90.0000
_cell_formula_units_Z            4
_cell_length_a                   24.185(4)
_cell_length_b                   24.185(4)
_cell_length_c                   21.599(4)
_cell_measurement_reflns_used    23427
_cell_measurement_temperature    173
_cell_measurement_theta_max      27.50
_cell_measurement_theta_min      3.30
_cell_volume                     12634(4)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r4'
_computing_data_collection
'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r4'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      173
_diffrn_detector_area_resol_mean 29.257
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Rigaku Saturn70'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0633
_diffrn_reflns_limit_h_max       31
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       30
_diffrn_reflns_limit_k_min       -31
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            100125
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.107
_exptl_absorpt_correction_T_max  0.895
_exptl_absorpt_correction_T_min  0.819
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'REQAB (Rigaku, 1998)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.364
_exptl_crystal_description       block
_exptl_crystal_F_000             5402.40
_exptl_crystal_size_max          0.100
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.720
_refine_diff_density_min         -0.790
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.093
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     360
_refine_ls_number_reflns         7663
_refine_ls_number_restraints     0
_refine_ls_R_factor_gt           0.0727
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.1131P)^2^+13.6292P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.2187
_reflns_number_gt                5914
_reflns_number_total             7663
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            ic301348f_si_002_3.cif
_cod_data_source_block           (2)
_cod_database_code               4330836