Ro‐vibrational Spectra of (para‐H₂)_N‐CH₄ in He Droplets

Abstract

In this work, we report on the infrared spectroscopic study of clusters of CH molecules with up to N=80 para-hydrogen molecules assembled inside He droplets. Upon increase of the number of the added para-hydrogen molecules up to about N=12, both the rotational constant, B, and the origin frequency of the υ band of CH decrease gradually. In the range of 6 ≤N≤12, the spectra indicate some abrupt changes of B and υ with both values being approximately constant at N≥12. The origin of this effect is discussed. Comparison of the spectra of methane molecules in para-hydrogen clusters to that in solid para-hydrogen is also presented.