Spectral Signatures of Protonated Noble Gas Clusters of Ne, Ar, Kr, and Xe: From Monomers to Trimers

Abstract

The structures and spectral features of protonated noble gas clusters are examined using a first principles approach. Protonated noble gas monomers (NgH+) and dimers (NgH+Ng) have a linear structure, while the protonated noble gas trimers (Ng3H+) can have a T-shaped or linear structure. Successive binding energies for these complexes are calculated at the CCSD(T)/CBS level of theory. Anharmonic simulations for the dimers and trimers unveil interesting spectral features. The symmetric NgH+Ng are charactized by a set of progression bands, which involves one quantum of the asymmetric Ng-H+ stretch with multiple quanta of the symmetric Ng-H+ stretch. Such a spectral signature is very robust and is predicted to be observed in both T-shaped and linear isomers of Ng3H+. Meanwhile, for selected asymmetric NgH+Ng’, a Fermi resonance interaction involving the first overtone of the proton bend with the proton stretch is predicted to occur in ArH+Kr and XeH+Kr.

Approaching the “Zundel” Limit: Tuning the Vibrational Coupling in N2H+Ng, Ng = {He, Ne, Ar, Kr, Xe, and Rn}

“…This frequency is close to that of the corresponding ν H + band for Ar 2 H + , which is at 989 cm −1 . 35,38,41,43 Furthermore, combination bands involving ν int + ν H + and 2ν int + ν H + are seen as bands at 1121 cm −1 and 1424 cm −1 . On the other hand, the ν NN band is seen as a moderate peak at 2370 cm −1 .…”

“…20,35−44 In addition to the bright ν H + band, our past simulations have shown that a strong progression of combination bands (nν int + ν H + ), which involves ν H + and multiple quanta of the A•••A intermolecular stretch nν int is observed for symmetric PBDs. Such combination bands are very pronounced in NgH + Ng 35,41,43 and N 2 H + N 2 . 13,20 In the present work, theoretical simulations were performed to investigate the vibrational structure of N 2 H + Ng, Ng = {He, Ne, Ar, Kr, Xe, and Rn}.…”

“…The resulting complex possesses interesting spectral features. ,− In addition to the bright ν H + band, our past simulations have shown that a strong progression of combination bands ( n ν int + ν H + ), which involves ν H + and multiple quanta of the A···A intermolecular stretch n ν int is observed for symmetric PBDs. Such combination bands are very pronounced in NgH + Ng ,, and N 2 H + N 2 . , …”

“…During the past few years, our group has been active in investigating the vibrational structures of symmetric PBDs. ,− In these complexes, the H + is sandwiched between two identical species (AH + A). The resulting complex possesses interesting spectral features. ,− In addition to the bright ν H + band, our past simulations have shown that a strong progression of combination bands ( n ν int + ν H + ), which involves ν H + and multiple quanta of the A···A intermolecular stretch n ν int is observed for symmetric PBDs. Such combination bands are very pronounced in NgH + Ng ,, and N 2 H + N 2 . , …”

Rotational State-to-State Rate Coefficients of HeHNe+ by Collision with He at Low Temperatures

“…The recent astronomical observations of HeH + and ArH + − have increased the interest in molecules bearing noble atoms . Several molecules of this type that could form in the interstellar medium (ISM) have been studied since these detections. − New searches for the noble gas species have also been carried out in recent years …”