Different mechanisms at different temperatures for the ring-opening polymerization of lactide catalyzed by binuclear magnesium and zinc alkoxides.
Sun, Yangyang; Cui, Yaqin; Xiong, Jiao; Dai, Zhongran; Tang, Ning; Wu, Jincai; Dalton transactions (Cambridge, England : 2003) 44 (2015) 16383–16391; doi:10.1039/c5dt01784j

data_7036166
_publ_section_title
;
 Different mechanisms at different temperatures for the ring-opening
 polymerization of lactide catalyzed by binuclear magnesium and zinc
 alkoxides.
;
_journal_issue                   37
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              16383
_journal_page_last               16391
_journal_paper_doi               10.1039/c5dt01784j
_journal_volume                  44
_journal_year                    2015
_chemical_formula_moiety         '1.5(C6 H6), C58 H82 N4 O4 Zn2, C3.5 H4'
_chemical_formula_sum            'C70.5 H95 N4 O4 Zn2'
_chemical_formula_weight         1193.24
_chemical_name_systematic
;
 ? 
;
_space_group_crystal_system      orthorhombic
_space_group_IT_number           56
_space_group_name_Hall           '-P 2ab 2ac'
_space_group_name_H-M_alt        'P c c n'
_symmetry_space_group_name_Hall  '-P 2ab 2ac'
_symmetry_space_group_name_H-M   'P c c n'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     iterative
_atom_sites_solution_secondary   difmap
_audit_creation_date             2014-10-03
_audit_creation_method
;
  Olex2 1.1
  (compiled 2011.11.01 svn.r2039, GUI svn.r3906)
;
_audit_update_record
;
2014-10-03 deposited with the CCDC.
2015-08-14 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   29.0531(7)
_cell_length_b                   21.5787(10)
_cell_length_c                   20.9114(6)
_cell_measurement_reflns_used    5556
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.7840
_cell_measurement_theta_min      3.5100
_cell_volume                     13109.9(8)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_molecular_graphics
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_publication_material
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_structure_refinement
;
XL, G.M. Sheldrick, Acta Cryst.
(2008). A64, 112-122
;
_computing_structure_solution
'SUPERFLIP, J. Appl. Cryst. (2007) 40, 786-790'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 16.0733
_diffrn_measured_fraction_theta_full 0.9969
_diffrn_measured_fraction_theta_max 0.8969
_diffrn_measurement_details
;
  1 omega  -44.00   19.60   1.2000   30.0000
omega____ theta____ kappa____ phi______ frames
    -      -19.5262   77.0000    0.0000 53

  2 omega    7.00   43.00   1.2000   30.0000
omega____ theta____ kappa____ phi______ frames
    -       22.6512  -57.0000   30.0000 30

  3 omega  -55.00   47.00   1.2000   30.0000
omega____ theta____ kappa____ phi______ frames
    -       22.6512  -19.0000   90.0000 85
;
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_UB_11      0.0039167000
_diffrn_orient_matrix_UB_12      0.0316903000
_diffrn_orient_matrix_UB_13      0.0072571000
_diffrn_orient_matrix_UB_21      -0.0240559000
_diffrn_orient_matrix_UB_22      0.0047903000
_diffrn_orient_matrix_UB_23      0.0030285000
_diffrn_orient_matrix_UB_31      0.0013511000
_diffrn_orient_matrix_UB_32      -0.0074143000
_diffrn_orient_matrix_UB_33      0.0329722000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.0748
_diffrn_reflns_av_unetI/netI     0.0806
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -34
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            36924
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.02
_diffrn_source                   'SuperNova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.781
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.31188
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light yellow'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.209
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             5104
_exptl_crystal_preparation       'toluene solvent'
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.698
_refine_diff_density_min         -1.090
_refine_diff_density_rms         0.093
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     734
_refine_ls_number_reflns         11495
_refine_ls_number_restraints     50
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.1105
_refine_ls_R_factor_gt           0.0688
_refine_ls_shift/su_max          0.016
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0819P)^2^+28.2112P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1631
_refine_ls_wR_factor_ref         0.2034
_reflns_number_gt                7521
_reflns_number_total             11495
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5dt01784j2.cif
_cod_data_source_block           hdsb1021
_cod_depositor_comments
'Adding full bibliography for 7036166--7036168.cif.'
_cod_original_formula_sum        'C70.50 H95 N4 O4 Zn2'
_cod_database_code               7036166
_reflns_odcompleteness_completeness 99.69
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Restrained distances
 C64-C66_$1 = C66-C64_$1
 1.38 with sigma of 0.02
3. Rigid bond restraints
 C67, C68, C69, C70, C71, C72
 with sigma for 1-2 distances of 0.001 and sigma for 1-3 distances of 0.001
4. Uiso/Uaniso restraints and constraints
C67 \\sim C68 \\sim C69 \\sim C70 \\sim C71 \\sim C72: within 1.7A with sigma
of 0.002 and sigma for terminal atoms of 0.004
5. Others
 Fixed Sof: HF(0.5) HG(0.5) HH(0.5)
6.a Ternary CH refined with riding coordinates:
 C21(H21)
6.b Secondary CH2 refined with riding coordinates:
 C8(H8A,H8B), C9(H9A,H9B), C10(H10A,H10B), C11(H11A,H11B), C12(H12A,H12B),
 C13(H13A,H13B), C52(H52A,H52B)
6.c Aromatic/amide H refined with riding coordinates:
 C67(H), C68(HA), C69(HB), C70(HC), C71(HD), C72(HE), C3(H3), C5(H5), C7(H7),
 C14(H14), C18(H18), C20(H20), C25(H25), C27(H27), C54(H54), C55(H55), C56(H56),
  C57(H57), C58(H58), C61(HI), C62(HJ), C63(HK), C64(HL), C65(HM), C66(HN)
6.d Fitted hexagon refined as free rotating group:
 C67(C68,C69,C70,C71,C72)
6.e Idealised Me refined as rotating group:
 C29(H29A,H29B,H29C), C30(H30A,H30B,H30C), C31(H31A,H31B,H31C), C33(H33A,H33B,
 H33C), C34(H34A,H34B,H34C), C35(H35A,H35B,H35C), C37(H37A,H37B,H37C), C38(H38A,
 H38B,H38C), C39(H39A,H39B,H39C), C41(H41A,H41B,H41C), C42(H42A,H42B,H42C),
 C43(H43A,H43B,H43C), C45(H45A,H45B,H45C), C46(H46A,H46B,H46C), C47(H47A,H47B,
 H47C), C49(H49A,H49B,H49C), C50(H50A,H50B,H50C), C51(H51A,H51B,H51C), C59(HF,
 HG,HH)
;