Trinuclear and Tetranuclear Magnesium Alkoxide Clusters as Highly Active Initiators for Ring-Opening Polymerization of l-Lactide.
Gao, Yuan; Dai, Zhongran; Zhang, Jinjin; Ma, Xinxian; Tang, Ning; Wu, Jincai; Inorganic chemistry 53 (2014) 716–726; doi:10.1021/ic401459a

data_4337163
_publ_section_title
;
 Trinuclear and Tetranuclear Magnesium Alkoxide Clusters as Highly Active
 Initiators for Ring-Opening Polymerization of l-Lactide.
;
_journal_issue                   2
_journal_name_full               'Inorganic chemistry'
_journal_page_first              716
_journal_page_last               726
_journal_paper_doi               10.1021/ic401459a
_journal_volume                  53
_journal_year                    2014
_chemical_formula_moiety         'C40 H74 Mg3 N4 O6'
_chemical_formula_sum            'C40 H74 Mg3 N4 O6'
_chemical_formula_weight         779.96
_space_group_IT_number           14
_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                 93.8503(13)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.0188(2)
_cell_length_b                   17.3708(2)
_cell_length_c                   16.2816(2)
_cell_measurement_reflns_used    13446
_cell_measurement_temperature    100.00(10)
_cell_measurement_theta_max      72.4795
_cell_measurement_theta_min      3.7223
_cell_volume                     4520.28(9)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.20 (release 27-06-2012 CrysAlis171 .NET)
(compiled Jul 11 2012,15:38:31)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.20 (release 27-06-2012 CrysAlis171 .NET)
(compiled Jul 11 2012,15:38:31)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.20 (release 27-06-2012 CrysAlis171 .NET)
(compiled Jul 11 2012,15:38:31)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100.00(10)
_diffrn_detector_area_resol_mean 16.0733
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'SuperNova (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0314
_diffrn_reflns_av_sigmaI/netI    0.0305
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            28044
_diffrn_reflns_theta_full        72.63
_diffrn_reflns_theta_max         72.63
_diffrn_reflns_theta_min         3.73
_exptl_absorpt_coefficient_mu    0.973
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.84738
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.20 (release 27-06-2012 CrysAlis171 .NET)
(compiled Jul 11 2012,15:38:31)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.146
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1704
_exptl_crystal_size_max          0.3000
_exptl_crystal_size_mid          0.2000
_exptl_crystal_size_min          0.1900
_refine_diff_density_max         0.317
_refine_diff_density_min         -0.228
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     494
_refine_ls_number_reflns         8942
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0371
_refine_ls_R_factor_gt           0.0334
_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^)+(0.0496P)^2^+1.2949P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0891
_refine_ls_wR_factor_ref         0.0924
_reflns_number_gt                8104
_reflns_number_total             8942
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ic401459a_si_001.cif
_cod_data_source_block           gy2
_cod_original_cell_volume        4520.26(11)
_cod_database_code               4337163