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_1575220
_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 N2 O6 Si '
_chemical_formula_sum            'C56 H54 N2 O6 Si'
_chemical_formula_weight         879.10
_chemical_properties_physical    Air-sensitive
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -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                106.669(2)
_cell_angle_beta                 93.269(2)
_cell_angle_gamma                90.445(2)
_cell_formula_units_Z            2
_cell_length_a                   8.9542(5)
_cell_length_b                   14.7938(8)
_cell_length_c                   20.8352(11)
_cell_measurement_reflns_used    9242
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.5505
_cell_measurement_theta_min      2.279
_cell_volume                     2638.8(2)
_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 0.999
_diffrn_measured_fraction_theta_max 0.995
_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  0.0733
_diffrn_reflns_av_unetI/netI     0.0319
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            225081
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.648
_diffrn_reflns_theta_min         1.989
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_current           1.4
_diffrn_source_type              'Incoatec I\ms'
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.6724
_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            yellow
_exptl_crystal_density_diffrn    1.106
_exptl_crystal_description       plate
_exptl_crystal_F_000             932
_exptl_crystal_recrystallization_method
'Vapor diffusion of n-pentane into DCM solution at room temperature.'
_exptl_crystal_size_max          0.90
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.19
_refine_diff_density_max         0.773
_refine_diff_density_min         -0.438
_refine_diff_density_rms         0.079
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.086
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     598
_refine_ls_number_reflns         16236
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.086
_refine_ls_R_factor_all          0.0711
_refine_ls_R_factor_gt           0.0613
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0659P)^2^+3.4912P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1615
_refine_ls_wR_factor_ref         0.1677
_reflns_Friedel_coverage         0.000
_reflns_number_gt                13790
_reflns_number_total             16236
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc03200h2.cif
_cod_data_source_block           mo_lst256_a_sq
_cod_depositor_comments
'Adding full bibliography for 1575220--1575222.cif.'
_cod_database_code               1575220
_shelx_shelxl_version_number     2019/1
_diffrn_measurement_ambient_temperature_device_make 'Oxford Cryostream 700'
_shelx_res_checksum              37493
_shelx_fab_checksum              9396