Dicationic and zwitterionic catalysts for the amine-initiated, immortal ring-opening polymerisation of rac-lactide: facile synthesis of amine-terminated, highly heterotactic PLA.
Clark, Lawrence; Cushion, Michael G; Dyer, Hellen E; Schwarz, Andrew D; Duchateau, Robbert; Mountford, Philip; Chemical communications (Cambridge, England) 46 (2009) 273–275; doi:10.1039/b919162c

data_7105151
_publ_section_title
;
 Dicationic and zwitterionic catalysts for the amine-initiated,
 immortal ring-opening polymerisation of rac-lactide: facile synthesis
 of amine-terminated, highly heterotactic PLA.
;
_journal_issue                   2
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              273
_journal_page_last               275
_journal_paper_doi               10.1039/b919162c
_journal_volume                  46
_journal_year                    2009
_chemical_formula_moiety         'C79 H92 B2 N6 O4 Y1, 0.75 (O1 C4 H8)'
_chemical_formula_sum            'C82 H98 B2 N6 O4.75 Y'
_chemical_formula_weight         1354.24
_chemical_name_common
'(Y(H(Me2pz)3)(OiPr)(THF)3)(BPh4)2 . 0.75(THF)'
_chemical_name_systematic
;
[Y{H(Me2pz)3}(OiPr)(THF)3][BPh4]2 . 0.75(THF)
;
_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
_cell_angle_alpha                111.9457(6)
_cell_angle_beta                 107.6075(5)
_cell_angle_gamma                94.1956(7)
_cell_formula_units_Z            4
_cell_length_a                   18.7867(2)
_cell_length_b                   20.3526(2)
_cell_length_c                   22.6804(3)
_cell_measurement_reflns_used    31373
_cell_measurement_temperature    150
_cell_measurement_theta_max      27
_cell_measurement_theta_min      5
_cell_volume                     7494.82(16)
_computing_cell_refinement       'DENZO/SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1997-2001).'
_computing_data_reduction        'DENZO/SCALEPACK (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'SIR92 (Altomare et al., 1994)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_device       'Nonius KappaCCD'
_diffrn_measurement_device_type  Area
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.069
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            57506
_diffrn_reflns_theta_full        25.798
_diffrn_reflns_theta_max         27.445
_diffrn_reflns_theta_min         5.090
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.832
_exptl_absorpt_correction_T_max  0.85
_exptl_absorpt_correction_T_min  0.85
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO/SCALEPACK (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.200
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2876
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         1.15
_refine_diff_density_min         -0.66
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.1275
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1756
_refine_ls_number_reflns         25134
_refine_ls_number_restraints     70
_refine_ls_R_factor_all          0.1724
_refine_ls_R_factor_gt           0.0853
_refine_ls_shift/su_max          0.001167
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982)
[weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)]
where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax
Method = Robust Weighting (Prince, 1982)
W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^
A~i~ are:
0.945 0.273 0.659
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1221
_refine_ls_wR_factor_gt          0.0702
_refine_ls_wR_factor_ref         0.0633
_reflns_limit_h_max              24
_reflns_limit_h_min              -24
_reflns_limit_k_max              26
_reflns_limit_k_min              -26
_reflns_limit_l_max              28
_reflns_limit_l_min              -29
_reflns_number_gt                30818
_reflns_number_total             33830
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   2.19
_oxford_diffrn_Wilson_scale      67.84
_oxford_refine_ls_r_factor_ref   0.0651
_oxford_refine_ls_scale          0.12648(11)
_oxford_reflns_number_all        57506
_oxford_reflns_threshold_expression_ref I>3.0\s(I)
_cod_data_source_file            b919162c.txt
_cod_data_source_block           Compound_1[BPh4]2
_cod_original_sg_symbol_H-M      'P -1 '
_cod_original_formula_sum        'C82 H98 B2 N6 O4.75 Y1'
_cod_database_code               7105151