Reversible Formation of Alkyl Radicals at [Fe<sub>4</sub>S<sub>4</sub>] Clusters and Its Implications for Selectivity in Radical SAM Enzymes.
Brown, Alexandra C.; Suess, Daniel L. M.; Journal of the American Chemical Society  (2020) –; doi:10.1021/jacs.0c05590

data_4135152
_publ_section_title
;
 Reversible Formation of Alkyl Radicals at [Fe<sub>4</sub>S<sub>4</sub>]
 Clusters and Its Implications for Selectivity in Radical SAM Enzymes.
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_paper_doi               10.1021/jacs.0c05590
_journal_year                    2020
_chemical_formula_sum            'C78.92 H95.01 F3 Fe4 N8 O4.98 S5'
_chemical_formula_weight         1676.10
_space_group_crystal_system      trigonal
_space_group_IT_number           167
_space_group_name_Hall           '-R 3 2"c'
_space_group_name_H-M_alt        'R -3 c :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2018/1
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                120
_cell_formula_units_Z            12
_cell_length_a                   22.8252(11)
_cell_length_b                   22.8252(11)
_cell_length_c                   53.979(3)
_cell_measurement_reflns_used    9970
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      29.36
_cell_measurement_theta_min      2.20
_cell_volume                     24355(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/1 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0450
_diffrn_reflns_av_unetI/netI     0.0121
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       32
_diffrn_reflns_limit_h_min       -32
_diffrn_reflns_limit_k_max       32
_diffrn_reflns_limit_k_min       -32
_diffrn_reflns_limit_l_max       77
_diffrn_reflns_limit_l_min       -76
_diffrn_reflns_number            377657
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.554
_diffrn_reflns_theta_min         1.277
_diffrn_source
'I\mS micro-focus sealed tube, multilayer optics'
_exptl_absorpt_coefficient_mu    0.890
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.6941
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Herbst-Irmer et al., 2015)'
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.371
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             10505
_exptl_crystal_size_max          0.600
_exptl_crystal_size_mid          0.600
_exptl_crystal_size_min          0.500
_refine_diff_density_max         0.302
_refine_diff_density_min         -0.541
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.139
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     705
_refine_ls_number_reflns         8290
_refine_ls_number_restraints     1977
_refine_ls_restrained_S_all      1.071
_refine_ls_R_factor_all          0.0542
_refine_ls_R_factor_gt           0.0351
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0260P)^2^+58.5342P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0806
_refine_ls_wR_factor_ref         0.0950
_reflns_Friedel_coverage         0.000
_reflns_number_gt                6332
_reflns_number_total             8290
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja0c05590_si_004.cif
_cod_data_source_block           '[4][OTf]'
_cod_original_cell_volume        24355(3)
_cod_database_code               4135152
_shelx_shelxl_version_number     2018/1
_shelx_estimated_absorpt_t_min   0.617
_shelx_estimated_absorpt_t_max   0.665
_shelx_res_checksum              78596
_shelx_hkl_checksum              66056