Long range vibrational energy transfer to dielectric surfaces

Abstract

Molecular vibrational energy transfer to the lattice vibrations of dielectric solids is investigated as a function of molecule to surface distance D. In the short range D−3 region, the rate shows an intense, narrow resonance at the surface vibrational polariton frequency. There is no resonance structure at the transverse optical frequency, where bulk absorption is maximized. The rates can be orders of magnitude faster than observed on reflective metallic surfaces in the infrared. The rates show a long range component extending beyond D? 1 μm which can be interpreted as transfer to lifetime broadened nonresonant vibrational polaritons. Experimental implications are considered in the cases of (a) vibrational deactivation in a gas–solid collision, and (b) chemical reactions near dielectric substrates or particles.