Effect of Pressure on Cyanide and Carbonyl Spectra in Solution

Abstract

The C–N vibration of CH3CN has been studied in a series of solvents, mostly substituted methanes, to 10 000 atmospheres pressure. Shapes of the curves of frequency versuspressure can be predicted reasonably well from a model which considers the interaction of each bond of the solvent molecule with the CN bonds. It is possible to estimate the relative contributions of dispersion, orientation, induction, and repulsion forces to the net shift. Similar measurements and calculations have been made for the C–O vibration in a series of compounds, using CS2 as the solvent. In this case, induction forces account for 65% of the observed interaction.