Validation of the existence of tetrameric species of potassium trimethylsilanolate in the gas phase with a theoretical cluster model: role of the counterion as charge localizer in the structure

Manuel Montejo; Aurora J Cruz Cabeza; Francisco Partal Ureña; Fernando Márquez; Juan Jesús López González

doi:10.1021/jp0686240

Validation of the existence of tetrameric species of potassium trimethylsilanolate in the gas phase with a theoretical cluster model: role of the counterion as charge localizer in the structure

J Phys Chem A. 2007 Apr 5;111(13):2629-33. doi: 10.1021/jp0686240. Epub 2007 Mar 14.

Authors

Manuel Montejo¹, Aurora J Cruz Cabeza, Francisco Partal Ureña, Fernando Márquez, Juan Jesús López González

Affiliation

¹ Physical and Analytical Chemistry Department, University of Jaén, Campus Las Lagunillas Edificio B-3, E-23071 Jaén, Spain.

PMID: 17388356
DOI: 10.1021/jp0686240

Abstract

We have investigated, theoretically, the structural properties of potassium trimethylsilanolate in the gas phase at a B3LYP/6-31+G* level. For this purpose, a simplified ionic cluster model based on potassium trimethylsilanolate tetramers, proposed in the literature as the structural units of this compound in the solid state, was developed. Furthermore, we compared the validity of the model with two simpler ones: a monomer of potassium trimethylsilanolate and a trimethylsilanolate anion in the gas phase. The developed ionic cluster model was found to be best in reproducing the experimental structure of potassium trimethylsilanolate, supporting, at the same time, the existence of such tetrameric species (previously identified experimentally from mass spectrometry data by Weiss et al.) in the gas phase. Finally, NBO calculations highlighted the important role of the potassium counterion as a charge localizer in the structure of these chemical species.