Alkaline earth metal complexes of a chiral polyether as initiator for the ring-opening polymerization of lactide.
Davin, Julien P.; Buffet, Jean-Charles; Spaniol, Thomas P.; Okuda, Jun; Dalton transactions (Cambridge, England : 2003) 41 (2012) 12612–12618; doi:10.1039/c2dt31309j

data_7030298
_publ_section_title
;
 Alkaline earth metal complexes of a chiral polyether as initiator for the
 ring-opening polymerization of lactide.
;
_journal_issue                   40
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              12612
_journal_page_last               12618
_journal_paper_doi               10.1039/c2dt31309j
_journal_volume                  41
_journal_year                    2012
_chemical_formula_moiety         'C24 H72 Ca2 N4 O2 Si8'
_chemical_formula_sum            'C24 H72 Ca2 N4 O2 Si8'
_chemical_formula_weight         753.74
_chemical_name_systematic
;
?
;
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_symmetry_cell_setting           monoclinic
_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                 97.8750(15)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   18.1714(18)
_cell_length_b                   23.153(2)
_cell_length_c                   21.826(2)
_cell_measurement_reflns_used    6991
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      26.74
_cell_measurement_theta_min      2.24
_cell_volume                     9096.1(15)
_computing_cell_refinement       'Bruker SMART (2001)'
_computing_data_collection       'Bruker SMART (2001)'
_computing_data_reduction        'Bruker SAINT+ (1999)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR 92 (Altomare et al, 1992)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.997
_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  0.0811
_diffrn_reflns_av_sigmaI/netI    0.0775
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       30
_diffrn_reflns_limit_k_min       -30
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            123697
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.39
_diffrn_reflns_theta_min         1.43
_exptl_absorpt_coefficient_mu    0.486
_exptl_absorpt_correction_T_max  0.9485
_exptl_absorpt_correction_T_min  0.8760
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Platon Mulabs'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.101
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             3296
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.990
_refine_diff_density_min         -0.497
_refine_diff_density_rms         0.065
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.850
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     801
_refine_ls_number_reflns         22744
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.850
_refine_ls_R_factor_all          0.0661
_refine_ls_R_factor_gt           0.0366
_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^)+(0.0275P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0733
_refine_ls_wR_factor_ref         0.0803
_reflns_number_gt                14770
_reflns_number_total             22744
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2dt31309j.txt
_cod_data_source_block           '[Ca{N(SiMe3)2}2(thf)2]'
_cod_original_cell_volume        9095.8(16)
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7030298