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_4119047
_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         'C114 H144 N6 O6 P4 Y2, 2(C6 H12)'
_chemical_formula_sum            'C126 H168 N6 O6 P4 Y2'
_chemical_formula_weight         2164.36
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 124.463(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   27.529(1)
_cell_length_b                   28.356(1)
_cell_length_c                   18.325(1)
_cell_measurement_reflns_used    12659
_cell_measurement_temperature    150.0(1)
_cell_measurement_theta_max      30.034
_cell_measurement_theta_min      0.998
_cell_volume                     11794.1(9)
_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 0.987
_diffrn_measured_fraction_theta_max 0.987
_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  0.0465
_diffrn_reflns_av_sigmaI/netI    0.0587
_diffrn_reflns_limit_h_max       33
_diffrn_reflns_limit_h_min       -33
_diffrn_reflns_limit_k_max       34
_diffrn_reflns_limit_k_min       -32
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            28082
_diffrn_reflns_theta_full        26.02
_diffrn_reflns_theta_max         26.02
_diffrn_reflns_theta_min         2.79
_exptl_absorpt_coefficient_mu    1.089
_exptl_absorpt_correction_T_max  0.8116
_exptl_absorpt_correction_T_min  0.7956
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO/SCALEPACK (Otwinowski & Minor, 1996)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.219
_exptl_crystal_description       Block
_exptl_crystal_F_000             4608
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_platon_squeeze_details
;
 A highly disordered C6H12 molecule was accounted for using the
 Platon SQUEEZE function.
;
_refine_diff_density_max         0.584
_refine_diff_density_min         -0.391
_refine_diff_density_rms         0.072
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.050
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     635
_refine_ls_number_reflns         11468
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0842
_refine_ls_R_factor_gt           0.0565
_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^)+(0.0259P)^2^+50.8374P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1136
_refine_ls_wR_factor_ref         0.1259
_reflns_number_gt                8593
_reflns_number_total             11468
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja310003v_si_003_2.cif
_cod_data_source_block           pa679bis
_cod_original_sg_symbol_H-M      'C 1 2/c 1 '
_cod_database_code               4119047