Heteroscorpionate rare-earth initiators for the controlled ring-opening polymerization of cyclic esters.
Otero, Antonio; Lara-Sánchez, Agustín; Fernández-Baeza, Juan; Alonso-Moreno, Carlos; Márquez-Segovia, Isabel; Sánchez-Barba, Luis F; Castro-Osma, José A; Rodríguez, Ana M; Dalton transactions (Cambridge, England : 2003) 40 (2011) 4687–4696; doi:10.1039/c0dt01678k

data_7015499
_publ_section_title
;
 Heteroscorpionate rare-earth initiators for the controlled
 ring-opening polymerization of cyclic esters.
;
_journal_issue                   17
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              4687
_journal_page_last               4696
_journal_paper_doi               10.1039/c0dt01678k
_journal_volume                  40
_journal_year                    2011
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C48 H74 N12 Nd2 O2 Si4, 2(C7 H8)'
_chemical_formula_sum            'C62 H90 N12 Nd2 O2 Si4'
_chemical_formula_weight         1436.30
_chemical_name_systematic
;
?
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 110.8830(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   11.7654(9)
_cell_length_b                   25.9552(18)
_cell_length_c                   13.4362(9)
_cell_measurement_reflns_used    4992
_cell_measurement_temperature    180(2)
_cell_measurement_theta_max      22.469
_cell_measurement_theta_min      2.257
_cell_volume                     3833.5(5)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      180(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0446
_diffrn_reflns_av_sigmaI/netI    0.0887
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       34
_diffrn_reflns_limit_k_min       -34
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            28800
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         1.80
_exptl_absorpt_coefficient_mu    1.446
_exptl_absorpt_correction_T_max  0.7322
_exptl_absorpt_correction_T_min  0.5819
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            purple
_exptl_crystal_density_diffrn    1.244
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1476
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.33
_exptl_crystal_size_min          0.23
_refine_diff_density_max         1.427
_refine_diff_density_min         -0.561
_refine_diff_density_rms         0.126
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.010(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.000
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     661
_refine_ls_number_reflns         18049
_refine_ls_number_restraints     112
_refine_ls_restrained_S_all      0.997
_refine_ls_R_factor_all          0.0743
_refine_ls_R_factor_gt           0.0542
_refine_ls_shift/su_max          0.057
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0746P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1311
_refine_ls_wR_factor_ref         0.1445
_reflns_number_gt                14220
_reflns_number_total             18049
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0dt01678k.txt
_cod_data_source_block           2
_cod_original_sg_symbol_H-M      P21
_cod_database_code               7015499