An NHC-Stabilized Silicon Analogue of Acylium Ion: Synthesis, Structure, Reactivity, and Theoretical Studies.
Ahmad, Syed Usman; Szilvási, Tibor; Irran, Elisabeth; Inoue, Shigeyoshi; Journal of the American Chemical Society 137 (2015) 5828–5836; doi:10.1021/jacs.5b01853

data_4129397
_publ_section_title
;
 An NHC-Stabilized Silicon Analogue of Acylium Ion: Synthesis, Structure,
 Reactivity, and Theoretical Studies.
;
_journal_issue                   17
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5828
_journal_page_last               5836
_journal_paper_doi               10.1021/jacs.5b01853
_journal_volume                  137
_journal_year                    2015
_chemical_formula_sum            'C74 H120 N4 O8 Si4'
_chemical_formula_weight         1306.10
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:05)
;
_cell_angle_alpha                90.00
_cell_angle_beta                 97.225(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.7865(2)
_cell_length_b                   17.7748(4)
_cell_length_c                   41.4406(9)
_cell_measurement_reflns_used    13741
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      72.6580
_cell_measurement_theta_min      2.6960
_cell_volume                     7882.2(3)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:05)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:05)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:05)
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      150.00(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 10.5435
_diffrn_detector_type            Atlas
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Single source at offset, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0873
_diffrn_reflns_av_sigmaI/netI    0.0748
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       49
_diffrn_reflns_limit_l_min       -37
_diffrn_reflns_number            54498
_diffrn_reflns_theta_full        67.50
_diffrn_reflns_theta_max         67.50
_diffrn_reflns_theta_min         2.71
_diffrn_source                   'sealed X-ray tube'
_diffrn_source_type              'SuperNova (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    1.103
_exptl_absorpt_correction_T_max  0.8095
_exptl_absorpt_correction_T_min  0.4368
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:05)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.101
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             2848
_exptl_crystal_size_max          0.90
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.20
_platon_squeeze_details
;
;
_refine_diff_density_max         1.502
_refine_diff_density_min         -0.842
_refine_diff_density_rms         0.078
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     939
_refine_ls_number_reflns         14180
_refine_ls_number_restraints     231
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.1079
_refine_ls_R_factor_gt           0.0789
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0623P)^2^+14.4520P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1803
_refine_ls_wR_factor_ref         0.1973
_reflns_number_gt                9814
_reflns_number_total             14180
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja5b01853_si_004.cif
_cod_data_source_block           cu-745a
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               4129397