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_7105082
_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         'C66 H140 Cl2 Li2 N6 O4 Si8 Yb2, 2(C7 H8)'
_chemical_formula_sum            'C80 H156 Cl2 Li2 N6 O4 Si8 Yb2'
_chemical_formula_weight         1921.69
_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                 99.936(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   16.5951(16)
_cell_length_b                   12.1850(10)
_cell_length_c                   25.657(2)
_cell_measurement_reflns_used    19021
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.0
_cell_volume                     5110.4(8)
_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      193(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  0.0454
_diffrn_reflns_av_sigmaI/netI    0.0364
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            48499
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.00
_exptl_absorpt_coefficient_mu    2.008
_exptl_absorpt_correction_T_max  0.448
_exptl_absorpt_correction_T_min  0.224
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            light-Yellow
_exptl_crystal_density_diffrn    1.249
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2004
_exptl_crystal_size_max          0.80
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.40
_refine_diff_density_max         1.320
_refine_diff_density_min         -1.028
_refine_diff_density_rms         0.080
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.163
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     481
_refine_ls_number_reflns         9342
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      1.172
_refine_ls_R_factor_all          0.0501
_refine_ls_R_factor_gt           0.0426
_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^)+(0.0351P)^2^+6.6371P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0912
_refine_ls_wR_factor_ref         0.0943
_reflns_number_gt                8438
_reflns_number_total             9342
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b915414k.txt
_cod_data_source_block           complexl
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7105082