Remarkable Stereocontrol in the Polymerization of Racemic Lactide Using Aluminum Initiators Supported by Tetradentate Aminophenoxide Ligands
Pimpa Hormnirun; Edward L. Marshall; Vernon C. Gibson; Andrew J. P. White; David J. Williams; Journal of the American Chemical Society 126 (2004) 2688–2689; doi:10.1021/ja038757o

data_4112282
_publ_section_title
;
 Remarkable Stereocontrol in the Polymerization of Racemic Lactide Using
 Aluminum Initiators Supported by Tetradentate Aminophenoxide Ligands
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2688
_journal_page_last               2689
_journal_paper_doi               10.1021/ja038757o
_journal_volume                  126
_journal_year                    2004
_chemical_formula_sum            'C23 H33 Al N2 O2'
_chemical_formula_weight         396.49
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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            8
_cell_length_a                   7.7325(10)
_cell_length_b                   15.6579(13)
_cell_length_c                   35.803(2)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    183(2)
_cell_measurement_theta_max      24.98
_cell_measurement_theta_min      10.99
_cell_volume                     4334.8(7)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      183(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker P4/RA'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0319
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            3203
_diffrn_reflns_theta_full        59.96
_diffrn_reflns_theta_max         59.96
_diffrn_reflns_theta_min         4.94
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.971
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.215
_exptl_crystal_description       needles
_exptl_crystal_F_000             1712
_exptl_crystal_size_max          0.37
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.235
_refine_diff_density_min         -0.314
_refine_diff_density_rms         0.049
_refine_ls_extinction_coef       0.00074(12)
_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   1.021
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     259
_refine_ls_number_reflns         3203
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.021
_refine_ls_R_factor_all          0.0572
_refine_ls_R_factor_gt           0.0451
_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^)+(0.0779P)^2^+1.0338P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1141
_refine_ls_wR_factor_ref         0.1202
_reflns_number_gt                2697
_reflns_number_total             3203
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja038757osi20030926_115748.cif
_cod_data_source_block           Complex_2
_cod_database_code               4112282