Monomethylaluminum and dimethylaluminum pyrrolylaldiminates for the ring-opening polymerization of rac-lactide: effects of ligand structure and coordination geometry.
Tabthong, Sittichoke; Nanok, Tanin; Kongsaeree, Palangpon; Prabpai, Samran; Hormnirun, Pimpa; Dalton transactions (Cambridge, England : 2003) 43 (2014) 1348–1359; doi:10.1039/c3dt52455h

data_7028619
_publ_section_title
;
 Monomethylaluminum and dimethylaluminum pyrrolylaldiminates for the
 ring-opening polymerization of rac-lactide: effects of ligand structure
 and coordination geometry.
;
_journal_issue                   3
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              1348
_journal_page_last               1359
_journal_paper_doi               10.1039/c3dt52455h
_journal_volume                  43
_journal_year                    2014
_chemical_absolute_configuration unk
_chemical_compound_source        Synthesis
_chemical_formula_moiety         'C25 H25 Al N4'
_chemical_formula_sum            'C25 H25 Al N4'
_chemical_formula_weight         408.485
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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           maXus
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.9362(3)
_cell_length_b                   12.7413(4)
_cell_length_c                   18.0469(4)
_cell_measurement_temperature    298
_cell_volume                     2284.74(11)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
'SIR97(Cascarano al.,Acta Cryst.,1996,A52,C-79)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_orient_matrix_type       X=UH
_diffrn_orient_matrix_UB_11      -0.01258
_diffrn_orient_matrix_UB_12      -0.03197
_diffrn_orient_matrix_UB_13      0.09460
_diffrn_orient_matrix_UB_21      -0.05497
_diffrn_orient_matrix_UB_22      -0.05044
_diffrn_orient_matrix_UB_23      -0.02436
_diffrn_orient_matrix_UB_31      0.03894
_diffrn_orient_matrix_UB_32      -0.03863
_diffrn_orient_matrix_UB_33      -0.00788
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           ' MoK\a'
_diffrn_radiation_wavelength_id  all
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            20685
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         0.00
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.107
_exptl_absorpt_correction_T_max  0.987
_exptl_absorpt_correction_T_min  0.623
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements
 Sortav (Blessing 1995)
;
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.188
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Prism
_exptl_crystal_F_000             864
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.162
_refine_diff_density_min         -0.126
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.2(2)
_refine_ls_extinction_coef       0.026(4)
_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   0.981
_refine_ls_hydrogen_treatment    refxyz
_refine_ls_matrix_type           full
_refine_ls_number_parameters     272
_refine_ls_number_reflns         4172
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.981
_refine_ls_R_factor_all          0.0739
_refine_ls_R_factor_gt           0.0460
_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^)+(0.0797P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1145
_refine_ls_wR_factor_ref         0.1284
_reflns_number_gt                2922
_reflns_number_total             4172
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3dt52455h.txt
_cod_data_source_block           3b
_cod_database_code               7028619