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_4302408
_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 La N3 O3 Si2'
_chemical_formula_sum            'C43 H76 La N3 O3 Si2'
_chemical_formula_weight         878.16
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 100.223(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.3838(12)
_cell_length_b                   20.663(2)
_cell_length_c                   22.752(3)
_cell_measurement_reflns_used    14580
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.1
_cell_volume                     4804.2(10)
_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      293(2)
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_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  0.0967
_diffrn_reflns_av_sigmaI/netI    0.1370
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            22563
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.05
_exptl_absorpt_coefficient_mu    0.976
_exptl_absorpt_correction_T_max  0.7584
_exptl_absorpt_correction_T_min  0.5921
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.214
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1856
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.30
_refine_diff_density_max         1.025
_refine_diff_density_min         -2.351
_refine_diff_density_rms         0.141
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.110
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     480
_refine_ls_number_reflns         8754
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.109
_refine_ls_R_factor_all          0.1512
_refine_ls_R_factor_gt           0.0961
_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^)+(0.1103P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2097
_refine_ls_wR_factor_ref         0.2408
_reflns_number_gt                5679
_reflns_number_total             8754
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic802177y_si_001_1.cif
_cod_data_source_block           complex1
_cod_original_cell_volume        4804.1(9)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4302408