Collect. Czech. Chem. Commun. 1997, 62, 816-820

Silicon-29 NMR Spectra of Trimethylsilylated Alcohols

Magdalena Kvíčalová, Jan Čermák, Vratislav Blechta and Jan Schraml

Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic,165 02 Prague 6-Suchdol, Czech Republic


29Si NMR spectra of trimethylsilyl (TMS) derivatives of 26 simple alcohols were measured under standardized conditions (i.e., in sufficiently diluted deuteriochloroform solutions). Due to association with the solvent the chemical shifts are in almost all cases larger than those reported earlier for different solutions. This observation is in agreement with the proposed mechanism of steric effects as being due to sterically controlled association with the solvent. The use of chloroform as a solvent enhances steric effects but at the same time it can reduce small differences due to polar effects in closely related compounds. In the studied class of compounds the gross dependence of the chemical shift on polar effects is not substantially affected by the change of the solvent.

Keywords: 29Si NMR; Trimethylsilyl derivatives; Alcohols; Polar effects; Steric effects.