Robust chiral zirconium alkoxide initiators for the room-temperature stereoselective ring-opening polymerisation of rac-lactide
Chmura, Amanda J.; Cousins, David M.; Davidson, Matthew G.; Jones, Matthew D.; Lunn, Matthew D.; Mahon, Mary F.; Dalton Transactions  (2008) 1437–1443; doi:10.1039/b716304e

data_7003469
_publ_section_title
;
 Robust chiral zirconium alkoxide initiators for the room-temperature
 stereoselective ring-opening polymerisation of rac-lactide
;
_journal_issue                   11
_journal_name_full               'Dalton Transactions'
_journal_page_first              1437
_journal_page_last               1443
_journal_paper_doi               10.1039/b716304e
_journal_year                    2008
_chemical_absolute_configuration ad
_chemical_formula_sum            'C38 H46 N2 O6 Ti'
_chemical_formula_weight         674.67
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      5
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.0000
_cell_angle_beta                 122.9800(10)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            2
_cell_length_a                   19.9450(2)
_cell_length_b                   9.4060(2)
_cell_length_c                   11.1810(2)
_cell_measurement_reflns_used    12553
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      3.51
_cell_volume                     1759.58(6)
_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_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
;
SIR97- Altomare A., Burla M.C., Camalli M., Cascarano G.L., Giacovazzo C. ,
Guagliardi A., Moliterni A.G.G., Polidori G.,Spagna R.
(1999) J. Appl. Cryst. 32, 115-119.
;
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'nonius kappa ccd'
_diffrn_measurement_method       ccd
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0386
_diffrn_reflns_av_sigmaI/netI    0.0417
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            15092
_diffrn_reflns_theta_full        27.47
_diffrn_reflns_theta_max         27.47
_diffrn_reflns_theta_min         3.76
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Nonius Kappa CCD'
_exptl_absorpt_coefficient_mu    0.291
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            block
_exptl_crystal_density_diffrn    1.273
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       yellow
_exptl_crystal_F_000             716
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.441
_refine_diff_density_min         -0.410
_refine_diff_density_rms         0.069
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     221
_refine_ls_number_reflns         3973
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.046
_refine_ls_R_factor_all          0.0430
_refine_ls_R_factor_gt           0.0367
_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^)+(0.0506P)^2^+0.6639P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0876
_refine_ls_wR_factor_ref         0.0911
_reflns_number_gt                3658
_reflns_number_total             3973
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b716304e.txt
_cod_data_source_block           (R2)2Ti(OiPr)2
_cod_original_cell_volume        1759.58(5)
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               7003469