Remarkable effect of alkali metal on polymerization of cyclic esters catalyzed by samarium-alkali metal multinuclear alkoxide clusters.
Sheng, Hongting; Shi, Jianhua; Feng, Yan; Wang, Hui; Jiao, Yonghua; Sheng, Hanjing; Zhang, Yong; Shen, Qi; Dalton transactions (Cambridge, England : 2003) 41 (2012) 9232–9240; doi:10.1039/c2dt30677h

data_7019817
_publ_section_title
;
 Remarkable effect of alkali metal on polymerization of cyclic esters
 catalyzed by samarium-alkali metal multinuclear alkoxide clusters.
;
_journal_issue                   30
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              9232
_journal_page_last               9240
_journal_paper_doi               10.1039/c2dt30677h
_journal_volume                  41
_journal_year                    2012
_chemical_formula_moiety         'C72 H184 K12 N18 Na4 O22 Sm2, 2(C7 H8)'
_chemical_formula_sum            'C86 H200 K12 N18 Na4 O22 Sm2'
_chemical_formula_weight         2700.50
_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                 90.310(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   15.5904(15)
_cell_length_b                   19.1307(19)
_cell_length_c                   22.611(2)
_cell_measurement_reflns_used    22932
_cell_measurement_temperature    153(2)
_cell_measurement_theta_max      25.3
_cell_measurement_theta_min      3.0
_cell_volume                     6743.8(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      153(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  0.0561
_diffrn_reflns_av_sigmaI/netI    0.0470
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            65572
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.01
_exptl_absorpt_coefficient_mu    1.306
_exptl_absorpt_correction_T_max  0.770
_exptl_absorpt_correction_T_min  0.533
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.330
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2828
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.20
_refine_diff_density_max         1.412
_refine_diff_density_min         -0.907
_refine_diff_density_rms         0.105
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.115
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     714
_refine_ls_number_reflns         12319
_refine_ls_number_restraints     20
_refine_ls_restrained_S_all      1.118
_refine_ls_R_factor_all          0.0731
_refine_ls_R_factor_gt           0.0575
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0488P)^2^+20.0262P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1249
_refine_ls_wR_factor_ref         0.1338
_reflns_number_gt                10257
_reflns_number_total             12319
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt30677h.txt
_cod_data_source_block           complex2
_cod_original_cell_volume        6743.6(11)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7019817