The distinct affinity of cyclopentadienyl ligands towards trivalent uranium over lanthanide ions. Evidence for cooperative ligation and back-bonding in the actinide complexes.
Mehdoui, Thouraya; Berthet, Jean-Claude; Thuery, Pierre; Ephritikhine, Michel; Dalton transactions (Cambridge, England : 2003)  (2005) 1263–1272; doi:10.1039/b419088b

data_7008207
_publ_section_title
;
 The distinct affinity of cyclopentadienyl ligands towards trivalent
 uranium over lanthanide ions. Evidence for cooperative ligation and
 back-bonding in the actinide complexes.
;
_journal_issue                   7
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1263
_journal_page_last               1272
_journal_paper_doi               10.1039/b419088b
_journal_year                    2005
_chemical_formula_sum            'C36 H52 Ce2 I2'
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_symmetry_cell_setting           tetragonal
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_symmetry_space_group_name_H-M   'P 43 21 2'
_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                   14.8670(3)
_cell_length_b                   14.8670(3)
_cell_length_c                   33.9336(12)
_cell_measurement_reflns_used    45357
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.68
_cell_measurement_theta_min      2.26
_cell_volume                     7500.3(3)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'Kappa-CCD software (Nonius B.V., 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 1999)'
_computing_publication_material  'SHELXTL (Sheldrick, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Nonius Kappa-CCD'
_diffrn_measurement_method       '\f 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  0.0958
_diffrn_reflns_av_sigmaI/netI    0.0497
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            45357
_diffrn_reflns_theta_full        25.68
_diffrn_reflns_theta_max         25.68
_diffrn_reflns_theta_min         2.26
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  0
_exptl_absorpt_coefficient_mu    4.065
_exptl_absorpt_correction_T_max  0.850
_exptl_absorpt_correction_T_min  0.296
_exptl_absorpt_correction_type   refdelf
_exptl_absorpt_process_details   'program DELABS from PLATON (Spek, 2000)'
_exptl_crystal_colour            'translucent light orange'
_exptl_crystal_density_diffrn    1.805
_exptl_crystal_density_meas      ?
_exptl_crystal_description       platelet
_exptl_crystal_F_000             3920
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.703
_refine_diff_density_min         -0.775
_refine_diff_density_rms         0.103
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.49(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     376
_refine_ls_number_reflns         7072
_refine_ls_number_restraints     12
_refine_ls_restrained_S_all      1.049
_refine_ls_R_factor_all          0.0582
_refine_ls_R_factor_gt           0.0418
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0072P)^2^+26.6972P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0753
_refine_ls_wR_factor_ref         0.0814
_reflns_number_gt                5721
_reflns_number_total             7072
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b419088b.txt
_cod_data_source_block           4
_cod_database_code               7008207