Tris(trimethylsilyl)sulfonium and methylbis(trimethylsilyl)sulfonium ions: preparation, NMR spectroscopy, and theoretical studies(1)
Tris(trimethylsilyl)sulfonium 1 and methylbis(trimethylsilyl)sulfonium 2 ions were prepared as long-lived species by reacting trimethylsilane and trityl tetrakis(pentafluorophenyl)borate (Ph(3)C(+) TPFPB) in the presence of precursor sulfides and characterized by (1)H, (13)C, and (29)Si NMR spectroscopy at -78 degrees C. Attempted preparation of dimethyl(trimethylsilyl)sulfonium ion under similar conditions failed as a result of the formation of the more stabilized trimethylsulfonium ion. Structures, and (13)C and (29)Si NMR chemical shifts were calculated by density functional theory (DFT)/IGLO methods. The calculated results agree well with the experimental data.
Prakash
GK
Donald P. and Katherine B. Loker Hydrocarbon Research Institute and Department of Chemistry, University of Southern California, University Park, Los Angeles, California 90089-1661, USA.
Bae
C
Wang
Q
Rasul
G
Olah
GA