1H, 13C and 29Si magnetic shielding in gaseous and liquid tetramethylsilane

Tetramethylsilane (TMS) is well-known as a reference standard of H-1, C-11 and Si-29 NMR chemical shifts. In the present study, we have observed TMS molecules in gaseous and liquid solutions. In the gas phase, the shielding parameters of TMS are monitored as the functions of density when xenon and krypton are applied as the buffer gases. It permits the evaluation of shielding in an isolated TMS molecule which is determined from the measurements of frequency and available nuclear magnetic moments. Having the shielding constants of an isolated TMS molecule, it is possible to proceed with the evaluation of H-1, C-13 and Si-29 TMS shielding in liquid state, which is extremely useful for the complete referencing of NMR spectra for protons, carbon-13 and silicon-29 nuclei. Consequently, the readings of chemical shifts and shielding parameters can be practically performed in the same experiment. (C) 2020 Published by Elsevier Inc.