X-ray Crystal Structures, Packing Behavior, and Thermal Stability Studies of a Homologous Series ofn-Alkyl-Substituted Polyhedral Oligomeric Silsesquioxanes
El Aziz, Youssef; Bassindale, Alan R.; Taylor, Peter G.; Stephenson, Richard A.; Hursthouse, Michael B.; Harrington, Ross W.; Clegg, William; Macromolecules 46 (2013) 988–; doi:10.1021/ma302229v

data_1508832
_publ_section_title
;
 X-ray Crystal Structures, Packing Behavior, and Thermal Stability Studies
 of a Homologous Series ofn-Alkyl-Substituted Polyhedral Oligomeric
 Silsesquioxanes
;
_journal_issue                   3
_journal_name_full               Macromolecules
_journal_page_first              988
_journal_paper_doi               10.1021/ma302229v
_journal_volume                  46
_journal_year                    2013
_chemical_formula_moiety         'C56 H120 O12 Si8'
_chemical_formula_sum            'C56 H120 O12 Si8'
_chemical_formula_weight         1210.24
_space_group_IT_number           85
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  '-P 4a'
_symmetry_space_group_name_H-M   'P 4/n :2'
_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                   21.4407(4)
_cell_length_b                   21.4407(4)
_cell_length_c                   15.4535(3)
_cell_measurement_reflns_used    28672
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.91
_cell_volume                     7104.0(2)
_computing_cell_refinement
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, R.W.W., 1998)'
_computing_data_collection       'COLLECT (Hooft, R.W.W., 1998)'
_computing_data_reduction
'DENZO (Otwinowski & Minor, 1997) & COLLECT (Hooft, R.W.W., 1998)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      120(2)
_diffrn_detector_area_resol_mean '4096x4096pixels / 62x62mm'
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker-Nonius APEX II CCD'
_diffrn_measurement_method       '\f & \w scans'
_diffrn_radiation_monochromator  '10cm confocal mirrors'
_diffrn_radiation_source         'Bruker-Nonius FR591 rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0725
_diffrn_reflns_av_sigmaI/netI    0.0686
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            38451
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.96
_exptl_absorpt_coefficient_mu    0.202
_exptl_absorpt_correction_T_max  0.990
_exptl_absorpt_correction_T_min  0.965
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2007/2 (Sheldrick, G.M., 2007)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.132
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Fragment
_exptl_crystal_F_000             2656
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.423
_refine_diff_density_min         -0.358
_refine_diff_density_rms         0.068
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     347
_refine_ls_number_reflns         8147
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.0981
_refine_ls_R_factor_gt           0.0519
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0239P)^2^+9.0109P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0973
_refine_ls_wR_factor_ref         0.1173
_reflns_number_gt                5181
_reflns_number_total             8147
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ma302229v_si_001.cif
_cod_data_source_block           2008src0962_7b
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Multi-scan' changed to
'multi-scan' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      'P 4/n'
_cod_database_code               1508832