Well-defined Ti4 pre-catalysts for the ring-opening polymerisation of lactide.
Cols, Jean-Marie E P; Taylor, Cameron E.; Gagnon, Kevin J.; Teat, Simon J.; McIntosh, Ruaraidh D.; Dalton transactions (Cambridge, England : 2003) 45 (2016) 17729–17738; doi:10.1039/c6dt03842e

data_7040946
_publ_section_title
;
 Well-defined Ti4 pre-catalysts for the ring-opening polymerisation of
 lactide.
;
_journal_issue                   44
_journal_name_full
'Dalton transactions (Cambridge, England : 2003)'
_journal_page_first              17729
_journal_page_last               17738
_journal_paper_doi               10.1039/c6dt03842e
_journal_volume                  45
_journal_year                    2016
_chemical_formula_moiety         'C72 H72 N4 O18 Ti4, 2(C2 H4 O0.5)'
_chemical_formula_sum            'C76 H80 N4 O19 Ti4'
_chemical_formula_weight         1545.04
_space_group_crystal_system      tetragonal
_space_group_IT_number           82
_space_group_name_Hall           'I -4'
_space_group_name_H-M_alt        'I -4'
_symmetry_space_group_name_Hall  'I -4'
_symmetry_space_group_name_H-M   'I -4'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2016-05-20
_audit_creation_method
;
Olex2 1.2
(compiled 2016.02.19 svn.r3266 for OlexSys, GUI svn.r5155)
;
_audit_update_record
;
2016-06-06 deposited with the CCDC.
2016-10-17 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   13.8620(5)
_cell_length_b                   13.8620(5)
_cell_length_c                   23.4683(8)
_cell_measurement_reflns_used    9994
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.11
_cell_measurement_theta_min      2.71
_cell_volume                     4509.6(3)
_computing_cell_refinement       'Bruker APEX2 v2014.9-0 (Bruker, 2014)'
_computing_data_collection       'Bruker APEX2 v2014.9-0 (Bruker, 2014)'
_computing_data_reduction        'SAINT v7.68A (Bruker, 2009)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100.0
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0342
_diffrn_reflns_av_unetI/netI     0.0242
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            36957
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        26.000
_diffrn_reflns_theta_max         27.117
_diffrn_reflns_theta_min         2.708
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.402
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.7022
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2008/1 (Bruker,2008) was used for absorption correction.
wR2(int) was 0.0566 before and 0.0469 after correction.
The Ratio of minimum to maximum transmission is 0.9419.
The \l/2 correction factor is 0.0015.
;
_exptl_crystal_colour            'clear light orange'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    orange
_exptl_crystal_density_diffrn    1.138
_exptl_crystal_description       block
_exptl_crystal_F_000             1608
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.4
_refine_diff_density_max         0.347
_refine_diff_density_min         -0.295
_refine_diff_density_rms         0.084
_refine_ls_abs_structure_details
;
 Flack x determined using 2190 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.033(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.068
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     247
_refine_ls_number_reflns         4978
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.0417
_refine_ls_R_factor_gt           0.0381
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0886P)^2^+0.5197P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1107
_refine_ls_wR_factor_ref         0.1145
_reflns_Friedel_coverage         0.946
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                4688
_reflns_number_total             4978
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6dt03842e2.cif
_cod_data_source_block           final_sq
_cod_depositor_comments
'Adding full bibliography for 7040945--7040948.cif.'
_cod_original_cell_volume        4509.6(4)
_cod_database_code               7040946
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Others
 Fixed Sof: O1AA(0.25) C2AA(0.5) H2AA(0.5) H2AB(0.5) C1AA(0.5) H1AA(0.5)
 H1AB(0.5)
3.a Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C2(H2A,H2B), C10(H10A,H10B), C2AA(H2AA,H2AB), C1AA(H1AA,H1AB)
3.b Aromatic/amide H refined with riding coordinates:
 C5(H5), C14(H14), C7(H7), C8(H8), C12(H12), C15(H15)
3.c Idealised Me refined as rotating group:
 C13A(H13A,H13B,H13C), C6A(H6AB,H6AC,H6AA)
;
_shelx_res_checksum              89839
_shelx_fab_checksum              33496
_olex2_submission_special_instructions 'No special instructions were received'