Planar lithium silolide: Aromaticity, with significant contribution of non-classical resonance structure
Fekete, Csaba; Kovacs, Ilona; Nyulaszi, Laszlo; Holczbauer, Tamas; Chem. Commun.  (2017) –; doi:10.1039/C7CC07004G

data_7120665
_publ_section_title
;
 Planar lithium silolide: Aromaticity, with significant contribution of
 non-classical resonance structure
;
_journal_name_full               'Chem. Commun.'
_journal_paper_doi               10.1039/C7CC07004G
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C35 H47 Li O Si3'
_chemical_formula_sum            'C35 H47 Li O Si3'
_chemical_formula_weight         574.93
_chemical_melting_point          'decomp. above 333K'
_chemical_name_systematic
(\h^5^-3,4-diphenyl-1-(2,4,6-trimethylphenyl)-2,5-bis(trimethylsilyl)-1-silacyclopentadien-1-yl)-tetrahydrofuran-lithium
_chemical_properties_physical
', Air-sensitive,Moisture-sensitive,Oxygen-sensitive'
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   direct
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2017-07-10 deposited with the CCDC.
2017-09-14 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 91.806(7)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.8347(3)
_cell_length_b                   19.7159(5)
_cell_length_c                   14.9148(4)
_cell_measurement_reflns_used    45071
_cell_measurement_temperature    112(2)
_cell_measurement_theta_max      68.28
_cell_measurement_theta_min      2.97
_cell_volume                     3478.37(16)
_computing_cell_refinement       'Crystal Clear V.1.4.1 (Rigaku/MSC, 2007)'
_computing_data_collection       'Crystal Clear V.1.4.1 (Rigaku/MSC, 2007)'
_computing_data_reduction        'Crystal Clear V.1.4.1 (Rigaku/MSC, 2007)'
_computing_molecular_graphics    'PLATON (Spek, 2009)'
_computing_publication_material  'PLATON (Spek, 2009)'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      112(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_details
;
 scan:  N=1,PHI=0.0,CHI=54.0,OMEGA=25.0,260.0,5.0,COUPLE=0.00                  
 scan:  N=2,PHI=90.0,CHI=54.0,OMEGA=25.0,260.0,5.0,COUPLE=0.00                 
 scan:  N=3,PHI=180.0,CHI=54.0,OMEGA=25.0,260.0,5.0,COUPLE=0.00                
 scan:  N=4,PHI=270.0,CHI=54.0,OMEGA=25.0,260.0,5.0,COUPLE=0.00                
 scan:  N=5,PHI=0.0,CHI=0.0,OMEGA=25.0,260.0,5.0,COUPLE=0.00                   
 Orientation Matrix:
    UB11 -0.0723 UB12  0.0047 UB13 -0.0360
    UB21 -0.0409 UB22  0.0107 UB23  0.0559
    UB31  0.0158 UB32  0.0494 UB33 -0.0087
    Matrix type: 'd*Trek'
;
_diffrn_measurement_device_type  'Rigaku RAXIS RAPID conversion'
_diffrn_measurement_method       dtprofit.ref
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0451
_diffrn_reflns_av_unetI/netI     0.0536
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            52455
_diffrn_reflns_point_group_measured_fraction_full 0.988
_diffrn_reflns_point_group_measured_fraction_max 0.987
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.232
_diffrn_reflns_theta_min         2.964
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    1.426
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.9248
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
;
T.Higashi, Numerical Absorption Correction, NUMABS, 2002
T.Higashi, Empirical Absorption Correction, 2001
;
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.098
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1240
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: tetrahydrofuran'
_exptl_crystal_size_max          0.280
_exptl_crystal_size_mid          0.250
_exptl_crystal_size_min          0.230
_refine_diff_density_max         0.457
_refine_diff_density_min         -0.387
_refine_diff_density_rms         0.051
_refine_ls_abs_structure_details
;
 Flack x determined using 4581 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.040(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     739
_refine_ls_number_reflns         12555
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.0558
_refine_ls_R_factor_gt           0.0469
_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^)+(0.0315P)^2^+2.7635P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0988
_refine_ls_wR_factor_ref         0.1061
_reflns_Friedel_coverage         0.919
_reflns_Friedel_fraction_full    0.979
_reflns_Friedel_fraction_max     0.976
_reflns_number_gt                11275
_reflns_number_total             12555
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7cc07004g2.cif
_cod_data_source_block           shelx
_cod_database_code               7120665
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.691
_shelx_estimated_absorpt_t_max   0.735
_shelx_res_checksum              67950