Yttrium Phosphasalen Initiators for rac-Lactide Polymerization: Excellent Rates and High Iso-Selectivities
Clare Bakewell; Thi-Phuong-Anh Cao; Nicholas Long; Xavier F. Le Goff; Audrey Auffrant; Charlotte K. Williams; Journal of the American Chemical Society 134 (2012) 20577–20580; doi:10.1021/ja310003v

data_4119046
_publ_contact_author_address
;Laboratoire DCPH
Ecole Polytechnique
Route de Saclay
F91128 Palaiseau
France
;
_publ_contact_author_email       c.k.williams@imperial.ac.uk
_publ_contact_author_name        'Charlotte K. Williams'
_publ_section_title
;
 Yttrium Phosphasalen Initiators for rac-Lactide Polymerization: Excellent
 Rates and High Iso-Selectivities
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              20577
_journal_page_last               20580
_journal_paper_doi               10.1021/ja310003v
_journal_volume                  134
_journal_year                    2012
_chemical_formula_moiety         'C60 H78 N3 O3 P2 Y, 1/2 (C5 H12)'
_chemical_formula_sum            'C62.5 H84 N3 O3 P2 Y'
_chemical_formula_weight         1076.18
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                101.860(1)
_cell_angle_beta                 94.240(1)
_cell_angle_gamma                104.373(1)
_cell_formula_units_Z            2
_cell_length_a                   10.657(1)
_cell_length_b                   15.472(1)
_cell_length_c                   19.027(1)
_cell_measurement_reflns_used    834
_cell_measurement_temperature    150.0(1)
_cell_measurement_theta_max      21.967
_cell_measurement_theta_min      0.998
_cell_volume                     2948.3(4)
_computing_cell_refinement       'DENZO (Otwinowski & Minor, 1997) & COLLECT'
_computing_data_collection       'COLLECT (Hooft, R.W.W., 1998)'
_computing_data_reduction        'DENZO & COLLECT'
_computing_molecular_graphics    'PLATON (Spek, 2009)'
_computing_publication_material  'PLATON (Spek, 2009)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare et al., 1999)'
_diffrn_ambient_temperature      150.0(1)
_diffrn_measured_fraction_theta_full 0.938
_diffrn_measured_fraction_theta_max 0.938
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0919
_diffrn_reflns_av_sigmaI/netI    0.1060
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            13959
_diffrn_reflns_theta_full        21.97
_diffrn_reflns_theta_max         21.97
_diffrn_reflns_theta_min         2.72
_exptl_absorpt_coefficient_mu    1.089
_exptl_absorpt_correction_T_max  0.9578
_exptl_absorpt_correction_T_min  0.8625
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO/SCALEPACK (Otwinowski & Minor, 1996)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.212
_exptl_crystal_description       Needle
_exptl_crystal_F_000             1146
_exptl_crystal_size_max          0.14
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.04
_platon_squeeze_details
;
 A highly disordered pentane molecule on a inversion 
 center was accounted for using the 
 Platon SQUEEZE function.
;
_refine_diff_density_max         0.538
_refine_diff_density_min         -0.480
_refine_diff_density_rms         0.084
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.102
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     641
_refine_ls_number_reflns         6749
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.102
_refine_ls_R_factor_all          0.1231
_refine_ls_R_factor_gt           0.0839
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0257P)^2^+15.0619P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1627
_refine_ls_wR_factor_ref         0.1817
_reflns_number_gt                4740
_reflns_number_total             6749
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja310003v_si_003_1.cif
_cod_data_source_block           aa704
_cod_original_cell_volume        2948.2(4)
_cod_original_sg_symbol_H-M      'P -1 '
_cod_original_formula_sum        'C62.50 H84 N3 O3 P2 Y'
_cod_database_code               4119046