Chromium(IV) Siloxide
Michael P. Marshak; Daniel G. Nocera; Inorganic Chemistry 52 (2013) 1173–1175; doi:10.1021/ic3023612

data_4333730
_publ_section_title
;
 Chromium(IV) Siloxide
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              1173
_journal_page_last               1175
_journal_paper_doi               10.1021/ic3023612
_journal_volume                  52
_journal_year                    2013
_chemical_formula_moiety         'C40 H92 Cr Na O5 Si4'
_chemical_formula_sum            'C40 H92 Cr Na O5 Si4'
_chemical_formula_weight         840.49
_chemical_name_common            (disilox)4CrNa(thf)
_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                   21.8239(12)
_cell_length_b                   18.8675(10)
_cell_length_c                   25.0854(14)
_cell_measurement_reflns_used    9345
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      29.56
_cell_measurement_theta_min      2.70
_cell_volume                     10329.2(10)
_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-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_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  0.0738
_diffrn_reflns_av_sigmaI/netI    0.0301
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            225134
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         29.61
_diffrn_reflns_theta_min         1.62
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.358
_exptl_absorpt_correction_T_max  0.7459
_exptl_absorpt_correction_T_min  0.6377
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2009)'
_exptl_crystal_colour            blue
_exptl_crystal_density_diffrn    1.081
_exptl_crystal_description       block
_exptl_crystal_F_000             3704
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.995
_refine_diff_density_min         -0.376
_refine_diff_density_rms         0.055
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     756
_refine_ls_number_reflns         14525
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0694
_refine_ls_R_factor_gt           0.0433
_refine_ls_shift/su_max          0.020
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0484P)^2^+6.3622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1042
_refine_ls_wR_factor_ref         0.1217
_reflns_number_gt                10723
_reflns_number_total             14525
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic3023612_si_002_1.cif
_cod_data_source_block           ortho
_cod_database_code               4333730