Heteroscorpionate Magnesium Alkyls Bearing Unprecedented Apical σ-C(sp3)-Mg Bonds: Heteroselective Ring-Opening Polymerization of rac-Lactide
Andrés Garcés; Luis F. Sánchez-Barba; Juan Fernández-Baeza; Antonio Otero; Manuel Honrado; Agustín Lara-Sánchez; Ana M. Rodríguez; Inorganic Chemistry 52 (2013) 12691–12701; doi:10.1021/ic401915b

data_4336609
_publ_contact_author
;                                                                               
     'S\'anchez-Barba, LF.'                                     
      Departamento de Qu\'imica Inorg\'anica y Anal\'itica 
      Universidad Rey Juan Carlos
      Mostoles
      28933-Madrid
      Spain.
;
_publ_contact_author_email       luisfernando.sanchezbarba@urjc.es
_publ_contact_author_phone       '+34 926295300'
_publ_section_title
;
 Heteroscorpionate Magnesium Alkyls Bearing Unprecedented Apical
 \s-C(sp3)-Mg Bonds: Heteroselective Ring-Opening Polymerization of
 rac-Lactide
;
_journal_name_full               'Inorganic Chemistry'
_journal_page_first              12691
_journal_page_last               12701
_journal_paper_doi               10.1021/ic401915b
_journal_volume                  52
_journal_year                    2013
_chemical_formula_moiety         'C56 H108 Mg4 N12 O2 Si4'
_chemical_formula_sum            'C56 H108 Mg4 N12 O2 Si4'
_chemical_formula_weight         1191.14
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_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                108.39(2)
_cell_angle_beta                 105.261(19)
_cell_angle_gamma                98.616(16)
_cell_formula_units_Z            2
_cell_length_a                   12.307(6)
_cell_length_b                   16.988(11)
_cell_length_c                   20.041(14)
_cell_measurement_reflns_used    1377
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      19.635
_cell_measurement_theta_min      3.127
_cell_volume                     3710(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX'
_computing_data_reduction        'Bruker SAINT, SADABS, XPREP'
_computing_molecular_graphics    'WINGX v1.70 (Farrugia, 1999)'
_computing_publication_material  'WINGX v1.70 (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.959
_diffrn_measured_fraction_theta_max 0.959
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'omega and phi 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  0.1385
_diffrn_reflns_av_sigmaI/netI    0.1845
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            19385
_diffrn_reflns_theta_full        20.81
_diffrn_reflns_theta_max         20.81
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    0.157
_exptl_absorpt_correction_T_max  0.9906
_exptl_absorpt_correction_T_min  0.9708
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.066
_exptl_crystal_description       prism
_exptl_crystal_F_000             1296
_exptl_crystal_size_max          0.19
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.211
_refine_diff_density_min         -0.264
_refine_diff_density_rms         0.051
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.929
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     732
_refine_ls_number_reflns         7443
_refine_ls_number_restraints     13
_refine_ls_restrained_S_all      0.934
_refine_ls_R_factor_all          0.1595
_refine_ls_R_factor_gt           0.0624
_refine_ls_shift/su_max          0.046
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1068
_refine_ls_wR_factor_ref         0.1403
_reflns_number_gt                3629
_reflns_number_total             7443
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic401915b_si_001_5.cif
_cod_data_source_block           12
_cod_database_code               4336609