Single-Component Catalyst/Initiators for the Organocatalytic Ring-Opening Polymerization of Lactide
Szilárd Csihony; Darcy A. Culkin; Alan C. Sentman; Andrew P. Dove; Robert M. Waymouth; James L. Hedrick; Journal of the American Chemical Society 127 (2005) 9079–9084; doi:10.1021/ja050909n

data_4111762
_publ_section_title
;
 Single-Component Catalyst/Initiators for the Organocatalytic Ring-Opening
 Polymerization of Lactide
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9079
_journal_page_last               9084
_journal_paper_doi               10.1021/ja050909n
_journal_volume                  127
_journal_year                    2005
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C22 H30 N2 O'
_chemical_formula_sum            'C22 H30 N2 O'
_chemical_formula_weight         338.48
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                   7.6487(13)
_cell_length_b                   14.877(3)
_cell_length_c                   16.803(3)
_cell_measurement_reflns_used    2081
_cell_measurement_temperature    119
_cell_measurement_theta_max      21.94
_cell_measurement_theta_min      2.42
_cell_volume                     1912.0(6)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      119
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type
;
;
_diffrn_measurement_method
;
;
_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  0.0647
_diffrn_reflns_av_sigmaI/netI    0.0627
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            8533
_diffrn_reflns_theta_full        24.75
_diffrn_reflns_theta_max         24.75
_diffrn_reflns_theta_min         1.83
_exptl_absorpt_coefficient_mu    0.072
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.84
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'Bruker AXS XPREP, SHELXTL v6.1 (2003)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.176
_exptl_crystal_description       rhombic
_exptl_crystal_F_000             736
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.195
_refine_diff_density_min         -0.205
_refine_diff_density_rms         0.046
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -10(10)
_refine_ls_extinction_coef       0.015(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     234
_refine_ls_number_reflns         1865
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.0699
_refine_ls_R_factor_gt           0.0471
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0697P)^2^+0.3735P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1088
_refine_ls_wR_factor_ref         0.1220
_reflns_number_gt                1449
_reflns_number_total             1865
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja050909nsi20050211_124625.cif
_cod_data_source_block           shelxl
_cod_original_cell_volume        1912.1(6)
_cod_database_code               4111762