Synthesis of Rare-Earth Metal Amides Bearing an Imidazolidine-Bridged Bis(phenolato) Ligand and Their Application in the Polymerization of l-Lactide
Zhongjian Zhang; Xiaoping Xu; Wenyi Li; Yingming Yao; Yong Zhang; Qi Shen; Yunjie Luo; Inorganic Chemistry 48 (2009) 5715–5724; doi:10.1021/ic802177y

data_4302412
_publ_section_title
;
Synthesis of Rare-Earth Metal Amides Bearing an Imidazolidine-Bridged
Bis(phenolato) Ligand and Their Application in the Polymerization
of l-Lactide
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              5715
_journal_page_last               5724
_journal_paper_doi               10.1021/ic802177y
_journal_volume                  48
_journal_year                    2009
_chemical_formula_moiety         'C43 H76 N3 O3 Si2 Yb, C7 H8'
_chemical_formula_sum            'C50 H84 N3 O3 Si2 Yb'
_chemical_formula_weight         1004.42
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 111.367(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.5090(18)
_cell_length_b                   32.814(4)
_cell_length_c                   12.0587(15)
_cell_measurement_reflns_used    15869
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.0
_cell_volume                     5346.5(11)
_computing_cell_refinement       CrystalClear
_computing_data_collection       CrystalClear
_computing_data_reduction        CrystalStructure
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      223(2)
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Rigaku Mercury'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0613
_diffrn_reflns_av_sigmaI/netI    0.0545
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       39
_diffrn_reflns_limit_k_min       -34
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            46446
_diffrn_reflns_theta_full        25.34
_diffrn_reflns_theta_max         25.34
_diffrn_reflns_theta_min         3.02
_exptl_absorpt_coefficient_mu    1.833
_exptl_absorpt_correction_T_max  0.693
_exptl_absorpt_correction_T_min  0.514
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.248
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2108
_exptl_crystal_size_max          0.41
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.20
_refine_diff_density_max         1.609
_refine_diff_density_min         -0.728
_refine_diff_density_rms         0.105
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.181
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     511
_refine_ls_number_reflns         9757
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.182
_refine_ls_R_factor_all          0.0705
_refine_ls_R_factor_gt           0.0563
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0256P)^2^+17.1628P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1053
_refine_ls_wR_factor_ref         0.1110
_reflns_number_gt                8374
_reflns_number_total             9757
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic802177y_si_001_5.cif
_cod_data_source_block           complex5
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4302412