A Highly Active Zinc Catalyst for the Controlled Polymerization of Lactide
Charlotte K. Williams; Laurie E. Breyfogle; Sun Kyung Choi; Wonwoo Nam; Victor G. Young; Marc A. Hillmyer; William B. Tolman; Journal of the American Chemical Society 125 (2003) 11350–11359; doi:10.1021/ja0359512

data_4114153
_publ_section_title
;
 A Highly Active Zinc Catalyst for the Controlled Polymerization of
 Lactide
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              11350
_journal_page_last               11359
_journal_paper_doi               10.1021/ja0359512
_journal_volume                  125
_journal_year                    2003
_chemical_formula_moiety         'C44 H80 N4 O4 Zn2'
_chemical_formula_sum            'C44 H80 N4 O4 Zn2'
_chemical_formula_weight         859.86
_space_group_IT_number           60
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2n 2ab'
_symmetry_space_group_name_H-M   'P b c n'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   38.339(3)
_cell_length_b                   17.0503(15)
_cell_length_c                   17.3185(15)
_cell_measurement_reflns_used    2529
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      47.475
_cell_measurement_theta_min      4.624
_cell_volume                     11321.0(17)
_computing_cell_refinement       'SAINT, Bruker'
_computing_data_collection       'SMART, Bruker'
_computing_data_reduction        'SAINT, Bruker'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR 92'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Siemens SMART Platform CCD'
_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  0.0683
_diffrn_reflns_av_sigmaI/netI    0.0887
_diffrn_reflns_limit_h_max       31
_diffrn_reflns_limit_h_min       -45
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            30924
_diffrn_reflns_theta_full        25.04
_diffrn_reflns_theta_max         25.04
_diffrn_reflns_theta_min         1.76
_exptl_absorpt_coefficient_mu    0.882
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.874535
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, R.Blessing, 1995'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.009
_exptl_crystal_description       plates
_exptl_crystal_F_000             3712
_exptl_crystal_size_max          0.2
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.461
_refine_diff_density_min         -0.458
_refine_diff_density_rms         0.075
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.947
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     485
_refine_ls_number_reflns         9979
_refine_ls_number_restraints     15
_refine_ls_restrained_S_all      0.954
_refine_ls_R_factor_all          0.0964
_refine_ls_R_factor_gt           0.0514
_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^)+(0.0682P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1182
_refine_ls_wR_factor_ref         0.1318
_reflns_number_gt                6142
_reflns_number_total             9979
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0359512si20030505_125202_2.cif
_cod_data_source_block           02203
_cod_database_code               4114153