Facile syntheses of bimetallic ytterbium bisamides stabilized by a flexible bridged bis(phenolato) ligand and the high activity for the polymerization of L-lactide
Zhongjian Zhang; Xiaoping Xu; Song Sun; Yingming Yao; Yong Zhang; Qi Shen; Chem. Commun.  (2009) 7414–7416; doi:10.1039/b915414k

data_7105083
_publ_section_title
;
 Facile syntheses of bimetallic ytterbium bisamides stabilized by a
 flexible bridged bis(phenolato) ligand and the high activity for the
 polymerization of L-lactide
;
_journal_name_full               'Chem. Commun.'
_journal_page_first              7414
_journal_page_last               7416
_journal_paper_doi               10.1039/b915414k
_journal_year                    2009
_chemical_formula_moiety         'C58 H124 N6 O2 Si8 Yb2, 2(C7 H8)'
_chemical_formula_sum            'C72 H140 N6 O2 Si8 Yb2'
_chemical_formula_weight         1692.70
_chemical_name_systematic
;
?
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                67.177(7)
_cell_angle_beta                 68.392(7)
_cell_angle_gamma                80.926(9)
_cell_formula_units_Z            1
_cell_length_a                   11.7680(11)
_cell_length_b                   14.8399(13)
_cell_length_c                   14.9402(9)
_cell_measurement_reflns_used    9086
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.0
_cell_volume                     2235.5(3)
_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 0.992
_diffrn_measured_fraction_theta_max 0.992
_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  0.0351
_diffrn_reflns_av_sigmaI/netI    0.0450
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            21813
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.05
_exptl_absorpt_coefficient_mu    2.227
_exptl_absorpt_correction_T_max  0.716
_exptl_absorpt_correction_T_min  0.429
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.257
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             882
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.15
_refine_diff_density_max         1.227
_refine_diff_density_min         -0.973
_refine_diff_density_rms         0.118
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.145
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     414
_refine_ls_number_reflns         8113
_refine_ls_number_restraints     14
_refine_ls_restrained_S_all      1.147
_refine_ls_R_factor_all          0.0460
_refine_ls_R_factor_gt           0.0392
_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^)+(0.0502P)^2^+1.0352P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0933
_refine_ls_wR_factor_ref         0.1026
_reflns_number_gt                7386
_reflns_number_total             8113
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b915414k.txt
_cod_data_source_block           complex2
_cod_database_code               7105083