Bridged Bis(amidinate) Ytterbium Alkoxide and Phenoxide: Syntheses, Structures, and Their High Activity for Controlled Polymerization of l-Lactide and ε-Caprolactone
Junfeng Wang; Yingming Yao; Yong Zhang; Qi Shen; Inorganic Chemistry 48 (2009) 744–751; doi:10.1021/ic801189j

data_4301185
_publ_section_title
;
Bridged Bis(amidinate) Ytterbium Alkoxide and Phenoxide: Syntheses,
Structures, and Their High Activity for Controlled Polymerization
of l-Lactide and \e-Caprolactone
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              744
_journal_page_last               751
_journal_paper_doi               10.1021/ic801189j
_journal_volume                  48
_journal_year                    2009
_chemical_formula_moiety         'C39 H61 N4 O3 Si2 Yb'
_chemical_formula_sum            'C39 H61 N4 O3 Si2 Yb'
_chemical_formula_weight         863.14
_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                 106.648(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   24.764(2)
_cell_length_b                   8.7551(6)
_cell_length_c                   20.0979(16)
_cell_measurement_reflns_used    12089
_cell_measurement_temperature    213(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.0
_cell_volume                     4174.8(6)
_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      213(2)
_diffrn_detector_area_resol_mean 7.31
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0431
_diffrn_reflns_av_sigmaI/netI    0.0340
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            39562
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.08
_exptl_absorpt_coefficient_mu    2.336
_exptl_absorpt_correction_T_max  0.496
_exptl_absorpt_correction_T_min  0.342
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.373
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1780
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         1.582
_refine_diff_density_min         -0.765
_refine_diff_density_rms         0.089
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.165
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     455
_refine_ls_number_reflns         7645
_refine_ls_number_restraints     4
_refine_ls_restrained_S_all      1.204
_refine_ls_R_factor_all          0.0583
_refine_ls_R_factor_gt           0.0431
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0222P)^2^+11.7518P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0798
_refine_ls_wR_factor_ref         0.0853
_reflns_number_gt                6197
_reflns_number_total             7645
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic801189j_si_001_1.cif
_cod_data_source_block           complex1
_cod_original_cell_volume        4174.7(6)
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4301185