Investigation on the vibrational and structural properties of a self-structured bridged silsesquioxane.
Creff, Gaëlle; Arrachart, Guilhem; Hermet, Patrick; Wadepohl, Hubert; Almairac, Robert; Maurin, David; Sauvajol, Jean-Louis; Carcel, Carole; Moreau, Joël J E; Dieudonné, Philippe; Man, Michel Wong Chi; Bantignies, Jean-Louis; Physical chemistry chemical physics : PCCP 14 (2012) 5672–5679; doi:10.1039/c2cp40250e

data_7207687
_publ_section_title
;
 Investigation on the vibrational and structural properties of a
 self-structured bridged silsesquioxane.
;
_journal_issue                   16
_journal_name_full               'Physical chemistry chemical physics : PCCP'
_journal_page_first              5672
_journal_page_last               5679
_journal_paper_doi               10.1039/c2cp40250e
_journal_volume                  14
_journal_year                    2012
_chemical_formula_sum            'C15 H28 N4 O5 Si'
_chemical_formula_weight         372.50
_space_group_IT_number           148
_symmetry_cell_setting           trigonal
_symmetry_Int_Tables_number      148
_symmetry_space_group_name_Hall  '-R 3'
_symmetry_space_group_name_H-M   'R -3 :H'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_block_code                michel
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            18
_cell_length_a                   35.463(3)
_cell_length_b                   35.463(3)
_cell_length_c                   7.8005(9)
_cell_measurement_reflns_used    5773
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.95
_cell_measurement_theta_min      2.30
_cell_volume                     8495.8(14)
_computing_cell_refinement
;
SAINT (Bruker AXS, 1997-2008). Includes estimated systematic errors
of the unit cell constants from Monte Carlo simulations.
;
_computing_data_collection       'SMART-5.631 (Bruker AXS, 2003)'
_computing_data_reduction
'SAINT (Bruker AXS, 1997-2008); SADABS (Bruker AXS, 2008)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR2004 (Giacovazzo et al., 2004)'
_diffrn_ambient_environment      'perfluoro polyether oil'
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 8.19
_diffrn_detector_type            CCD-PXL-KAF2
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device       'three-circle diffractometer'
_diffrn_measurement_device_type  'Bruker AXS Smart 1000'
_diffrn_measurement_method       '\f- and \w-scans'
_diffrn_measurement_specimen_support 'polyimid foil'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0475
_diffrn_reflns_av_sigmaI/netI    0.0255
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -41
_diffrn_reflns_limit_k_max       42
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            96145
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         1.99
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.157
_exptl_absorpt_correction_T_max  0.7463
_exptl_absorpt_correction_T_min  0.6628
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements (Blessing 1995)
SADABS (Sheldrick & Bruker AXS, 2004-2008)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.311
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       irregular
_exptl_crystal_F_000             3600
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         2.734
_refine_diff_density_min         -0.774
_refine_diff_density_rms         0.208
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   2.928
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     167
_refine_ls_number_reflns         3353
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      2.940
_refine_ls_R_factor_all          0.3174
_refine_ls_R_factor_gt           0.2631
_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^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.6365
_refine_ls_wR_factor_ref         0.6768
_reflns_number_gt                1951
_reflns_number_total             3353
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2cp40250e.txt
_cod_data_source_block           ex_mw1
_cod_original_cell_volume        8495.6(14)
_cod_original_sg_symbol_H-M      'R -3'
_cod_database_code               7207687