What distinguishes the strength and the effect of a Lewis base: insights with a strong chromogenic silicon Lewis acid.
Stoess, Lennart; Greb, Lutz; Chemical science 16 (2025) 15387–15395; doi:10.1039/d5sc03200h

data_1575222
_publ_section_title
;
 What distinguishes the strength and the effect of a Lewis base: insights
 with a strong chromogenic silicon Lewis acid.
;
_journal_issue                   34
_journal_name_full               'Chemical science'
_journal_page_first              15387
_journal_page_last               15395
_journal_paper_doi               10.1039/d5sc03200h
_journal_volume                  16
_journal_year                    2025
_chemical_formula_moiety
'C56 H54 Cl N2 O6 Si, C24 H20 P, 3.918(C H2 Cl2) '
_chemical_formula_sum            'C83.92 H81.84 Cl8.84 N2 O6 P Si'
_chemical_formula_weight         1586.81
_chemical_properties_physical    Air-sensitive
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_method
;FinalCif V137 by Daniel Kratzert, Freiburg 2024, 
https://dkratzert.de/finalcif.html
;
_audit_update_record
;
2024-11-15 deposited with the CCDC.	2025-07-23 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 101.651(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   23.7594(15)
_cell_length_b                   12.8395(8)
_cell_length_c                   27.1540(16)
_cell_measurement_reflns_used    9042
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25.6735
_cell_measurement_theta_min      2.2555
_cell_volume                     8112.9(9)
_computing_cell_refinement       'SAINT V8.40B'
_computing_data_collection
'Bruker BIS V6.2.15/2021-03-15 and APEX4 2021.10-0'
_computing_data_reduction        'SAINT V8.40B'
_computing_structure_refinement  'SHELXL-2019/1 (Sheldrick, 2019)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100(2)
_diffrn_detector                 CPAD
_diffrn_detector_area_resol_mean 7.41
_diffrn_detector_type            'Bruker PHOTON III'
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8 VENTURE dual wavelength Mo/Cu'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_measurement_specimen_support 'MiTeGen micromount'
_diffrn_radiation_monochromator  'mirror optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0981
_diffrn_reflns_av_unetI/netI     0.0259
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -29
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            511533
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.468
_diffrn_reflns_theta_min         1.897
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_current           1.41
_diffrn_source_type              'Incoatec I\ms'
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    0.393
_exptl_absorpt_correction_T_max  0.7454
_exptl_absorpt_correction_T_min  0.6796
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;SADABS-2016/2 - Bruker AXS area detector scaling and absorption correction: 
Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D., J. Appl. Cryst. 48 
(2015) 3-10
;
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.299
_exptl_crystal_description       plate
_exptl_crystal_F_000             3307
_exptl_crystal_recrystallization_method
'Vapor diffusion of pentane into a DCM solution at -40 \%C.'
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.708
_refine_diff_density_min         -0.781
_refine_diff_density_rms         0.061
_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     1034
_refine_ls_number_reflns         16709
_refine_ls_number_restraints     531
_refine_ls_restrained_S_all      1.064
_refine_ls_R_factor_all          0.0672
_refine_ls_R_factor_gt           0.0507
_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^)+(0.0507P)^2^+12.2483P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1242
_refine_ls_wR_factor_ref         0.1357
_reflns_Friedel_coverage         0.000
_reflns_number_gt                13191
_reflns_number_total             16709
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc03200h2.cif
_cod_data_source_block           mo_lst466A_a_sq
_cod_depositor_comments
'Adding full bibliography for 1575220--1575222.cif.'
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1575222
_shelx_shelxl_version_number     2019/1
_diffrn_measurement_ambient_temperature_device_make 'Oxford Cryostream 700'
_shelx_res_checksum              80151
_shelx_fab_checksum              40262