Highly active and stereoselective zirconium and hafnium alkoxide initiators for solvent-free ring-opening polymerization of rac-lactide.
Chmura, Amanda J; Davidson, Matthew G; Frankis, Catherine J; Jones, Matthew D; Lunn, Matthew D; Chemical communications (Cambridge, England)  (2008) 1293–1295; doi:10.1039/b718678a

data_7102967
_publ_section_title
;
 Highly active and stereoselective zirconium and hafnium alkoxide
 initiators for solvent-free ring-opening polymerization of
 rac-lactide.
;
_journal_issue                   11
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              1293
_journal_page_last               1295
_journal_paper_doi               10.1039/b718678a
_journal_year                    2008
_chemical_formula_sum            'C54 H87 Hf N O4'
_chemical_formula_weight         992.74
_chemical_name_systematic
;
?
;
_space_group_IT_number           78
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'P 4cw'
_symmetry_space_group_name_H-M   'P 43'
_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            4
_cell_length_a                   14.57000(10)
_cell_length_b                   14.57000(10)
_cell_length_c                   25.4100(2)
_cell_measurement_reflns_used    86119
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      3.51
_cell_volume                     5394.16(7)
_computing_cell_refinement       'HKL Scalepack (Otwinski & Minor, 1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction
'HKL Denzo & Scalepack (Otwinski & Minor 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'nonius kappa ccd'
_diffrn_measurement_method       ccd
_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  0.0362
_diffrn_reflns_av_sigmaI/netI    0.0228
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            81147
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         3.51
_exptl_absorpt_coefficient_mu    1.974
_exptl_absorpt_correction_T_max  0.5449
_exptl_absorpt_correction_T_min  0.4385
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.222
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2088
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.35
_refine_diff_density_max         0.517
_refine_diff_density_min         -1.250
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.432(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.064
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     762
_refine_ls_number_reflns         12310
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0264
_refine_ls_R_factor_gt           0.0228
_refine_ls_shift/su_max          0.010
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0164P)^2^+3.9735P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0504
_refine_ls_wR_factor_ref         0.0521
_reflns_number_gt                11451
_reflns_number_total             12310
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b718678a.txt
_cod_data_source_block
d:\mgdgroup\matthe~2\papers\zrc3\xrayre~1\test\k06mgd17
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Tetragonal' changed to 'tetragonal'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P43
_cod_database_code               7102967