A Dichromium(II) Bis(η8-pentalene) Double-Sandwich Complex with a Spin Equilibrium: Synthetic, Structural, Magnetic, and Theoretical Studies
Balazs, Gabor; Cloke, F. Geoffrey N.; Gagliardi, Laura; Green, Jennifer C.; Harrison, Andrew; Hitchcock, Peter B.; Shahi, Abdul Rehaman Moughal; Summerscales, Owen T.; Organometallics 27 (2008) 2013–; doi:10.1021/om701153t

data_4070960
_publ_section_title
;
 A Dichromium(II) Bis(\h8-pentalene) Double-Sandwich Complex with a Spin
 Equilibrium: Synthetic, Structural, Magnetic, and Theoretical Studies
;
_journal_issue                   9
_journal_name_full               Organometallics
_journal_page_first              2013
_journal_paper_doi               10.1021/om701153t
_journal_volume                  27
_journal_year                    2008
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C52 H92 Cr2 Si4'
_chemical_formula_sum            'C52 H92 Cr2 Si4'
_chemical_formula_weight         933.62
_chemical_name_systematic
;
 ?
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      15
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.3
_audit_creation_date             2005-10-06T09:55:58-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 118.579(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   21.713(2)
_cell_length_b                   13.2479(13)
_cell_length_c                   21.2951(18)
_cell_measurement_reflns_used    272643
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      26.022
_cell_measurement_theta_min      3.395
_cell_measurement_wavelength     0.71073
_cell_volume                     5379.2(9)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction
'HKL Denzo and Scalepack (Otwinowski & Minor 1997)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.973
_diffrn_measured_fraction_theta_max 0.973
_diffrn_measurement_device       '95mm CCD camera on \k-goniostat'
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'CCD rotation images, thick slices'
_diffrn_orient_matrix_type       'by Nonius Collect from scalepack cell'
_diffrn_orient_matrix_UB_11      -0.380583E-1
_diffrn_orient_matrix_UB_12      -0.473516E-1
_diffrn_orient_matrix_UB_13      -0.5292E-2
_diffrn_orient_matrix_UB_21      0.32577E-1
_diffrn_orient_matrix_UB_22      -0.317543E-1
_diffrn_orient_matrix_UB_23      0.469394E-1
_diffrn_orient_matrix_UB_31      -0.155178E-1
_diffrn_orient_matrix_UB_32      0.494699E-1
_diffrn_orient_matrix_UB_33      0.250646E-1
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0899
_diffrn_reflns_av_unetI/netI     0.0829
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -26
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            15523
_diffrn_reflns_theta_full        26
_diffrn_reflns_theta_max         26
_diffrn_reflns_theta_min         3.56
_diffrn_source                   'Enraf Nonius FR590'
_exptl_absorpt_coefficient_mu    0.525
_exptl_absorpt_correction_T_max  0.898
_exptl_absorpt_correction_T_min  0.608
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
        [c.f. r.h. blessing, acta cryst. (1995), a51, 33-38]
;
_exptl_crystal_colour            black
_exptl_crystal_density_diffrn    1.153
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2032
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         1.308
_refine_diff_density_min         -0.535
_refine_diff_density_rms         0.076
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.154
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         5152
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.154
_refine_ls_R_factor_all          0.1317
_refine_ls_R_factor_gt           0.0817
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0084P)^2^+29.0995P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1452
_refine_ls_wR_factor_ref         0.168
_reflns_number_gt                3539
_reflns_number_total             5152
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            om701153t_si.cif
_cod_data_source_block           oct405
_cod_original_cell_volume        5379.3(9)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4070960