Heterogeneous catalysts for the controlled ring-opening polymerisation of rac-lactide and homogeneous silsesquioxane model complexes
Jones, Matthew D.; Davidson, Matthew G.; Keir, Callum G.; Wooles, Ashley J.; Mahon, Mary F.; Apperley, David C.; Dalton Transactions  (2008) 3655–3657; doi:10.1039/b805274c

data_7004305
_publ_section_title
;
 Heterogeneous catalysts for the controlled ring-opening polymerisation
 of rac-lactide and homogeneous silsesquioxane model complexes
;
_journal_issue                   28
_journal_name_full               'Dalton Transactions'
_journal_page_first              3655
_journal_page_last               3657
_journal_paper_doi               10.1039/b805274c
_journal_year                    2008
_chemical_formula_sum            'C62 H140 O26 Si14 Ti2'
_chemical_formula_weight         1790.80
_chemical_name_systematic
;
?
;
_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                112.8870(10)
_cell_angle_beta                 91.380(1)
_cell_angle_gamma                90.600(1)
_cell_formula_units_Z            2
_cell_length_a                   15.7700(2)
_cell_length_b                   17.32200(10)
_cell_length_c                   18.9630(2)
_cell_measurement_reflns_used    58253
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      3.51
_cell_volume                     4769.78(9)
_computing_cell_refinement       'HKL Scalepack (Otwinski & Minor, 1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction
'HKL Denzo & Scalepack (Otwinski & Minor 1997)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
;
SIR97- Altomare A., Burla M.C., Camalli M., Cascarano G.L., Giacovazzo C. ,
Guagliardi A., Moliterni A.G.G., Polidori G.,Spagna R.
(1999) J. Appl. Cryst. 32, 115-119.
;
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'nonius kappa ccd'
_diffrn_measurement_method       ccd
_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  0.0457
_diffrn_reflns_av_sigmaI/netI    0.0424
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            97404
_diffrn_reflns_theta_full        27.52
_diffrn_reflns_theta_max         27.52
_diffrn_reflns_theta_min         3.54
_exptl_absorpt_coefficient_mu    0.407
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.247
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       block
_exptl_crystal_F_000             1920
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         1.493
_refine_diff_density_min         -0.647
_refine_diff_density_rms         0.074
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.022
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1126
_refine_ls_number_reflns         21875
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.0819
_refine_ls_R_factor_gt           0.0512
_refine_ls_shift/su_max          0.005
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0741P)^2^+4.6707P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1349
_refine_ls_wR_factor_ref         0.1591
_reflns_number_gt                14926
_reflns_number_total             21875
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b805274c.txt
_cod_data_source_block           complex3
_cod_original_cell_volume        4769.78(8)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7004305