Structure and Reactivity of Chromium(VI) Alkylidenes.
Wu, Pengcheng; Yap, Glenn P. A.; Theopold, Klaus H.; Journal of the American Chemical Society 140 (2018) 7088–7091; doi:10.1021/jacs.8b04882

data_4132561
_publ_section_title
;
 Structure and Reactivity of Chromium(VI) Alkylidenes.
;
_journal_issue                   23
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7088
_journal_page_last               7091
_journal_paper_doi               10.1021/jacs.8b04882
_journal_volume                  140
_journal_year                    2018
_chemical_absolute_configuration ad
_chemical_formula_sum            'C38 H47 Cr N2'
_chemical_formula_weight         583.77
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.8933(15)
_cell_length_b                   17.768(3)
_cell_length_c                   19.173(3)
_cell_measurement_reflns_used    3674
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      24.29
_cell_measurement_theta_min      2.29
_cell_volume                     3370.3(9)
_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-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      200(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker AXS APEX diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0525
_diffrn_reflns_av_unetI/netI     0.0770
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            19305
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.991
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.592
_diffrn_reflns_theta_min         2.124
_exptl_absorpt_coefficient_mu    0.366
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.6007
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'APEX2 (Bruker, 2007)'
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.150
_exptl_crystal_description       block
_exptl_crystal_F_000             1252
_exptl_crystal_size_max          0.396
_exptl_crystal_size_mid          0.380
_exptl_crystal_size_min          0.232
_refine_diff_density_max         0.310
_refine_diff_density_min         -0.273
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details
; 
 Flack x determined using 1817 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   -0.014(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     386
_refine_ls_number_reflns         7746
_refine_ls_number_restraints     19
_refine_ls_restrained_S_all      1.009
_refine_ls_R_factor_all          0.0845
_refine_ls_R_factor_gt           0.0515
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0563P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1059
_refine_ls_wR_factor_ref         0.1214
_reflns_Friedel_coverage         0.790
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.990
_reflns_number_gt                5553
_reflns_number_total             7746
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja8b04882_si_001.cif
_cod_data_source_block           kla0708
_cod_database_code               4132561
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.869
_shelx_estimated_absorpt_t_max   0.920
_shelx_res_checksum              85893
_shelx_hkl_checksum              12951