Collision-Induced Absorption of Hydrogen Deuteride Dissolved in Liquid Neon

Abstract

First observation of the collision-induced IR-fundamental band of hydrogen deuteride (HD) in liquid neon is described. A developed intracell rattling model yields highly accurate fits to the measured diffuse Q1-branch profiles enabling a detailed shape analysis of the adjacent spectral lines. Strong intracollisional anticorrelation found at the location of the permanent dipole-allowed R1(0) transition is interpreted in the frame of the Fano-Mori theory. A new striking narrowing effect (by 30%) is observed on the sharp Q(q)(1)(0) vibrational line with increasing HD concentration in solutions. The T1(0), U1(0) and a few pair transitions are identified in the spectrum.

Infrared and Raman Measurements of Halogen Bonding in Cryogenic Solutions

“…Cells similar to those described above can also be constructed by combining a cell body and a double-stage cryostat involving closed cycle helium cooling, or by combining a cell body with an LN 2 Dewar, heating cartridge, and proportional-integral-derivative (PID) controller. A typical cell of the first type, recently developed for experiments in LNe [59][60][61], is shown in Fig. 8.…”

New Line Narrowing Effects in the Infrared Collision-Induced Spectra of Molecular Hydrogens in Liquid Neon

“…This study was stimulated by the recently observed [6] unusual behavior of the sharp Q q 1 ð0Þ line of HD in liquid neon: by increasing x just from 0.01 to 0.04, the line width [half width at half height (HWHH)] dropped by one-third (from 3.2 to 2:1 cm À1 ). The line sharpness and the abnor-mally strong narrowing (instead of conventional concentration broadening) posed a paradox which at that moment could not be resolved because of the lack of experimental data.…”

“…Subsequently, the cell was allowed to warm up to 25 K and solvent gas, precooled with LN 2 , was slowly added. During condensation of the solvent, the temperature of the solution did not exceed 28 K. The use of a longer path length, as well as of quartz or sapphire windows instead of silicon ones, considerably increased the signal-to-noise ratio, so that weaker features could be studied with a much higher accuracy than previously [6].…”

“…r Þ. A refined form of the intracollisional spectrum W 0 ðuÞ [6] produced by impacts of a guest with the nearest atoms now incorporates the Egelstaff quantum asymmetry factor [7] and the slower decay exp½Àðu=2! c Þ 2=3 [8] at detunings u much greater than the inverse collision duration !…”

Infrared spectral profiles in liquids and atom-diatom interactions

“…Moreover, a rich structure has been found in the collision-induced absorption of N 2 in Ar ͑Ref. 30͒ and HD in liquid Ne, 31 the latter has been measured recently for the first time. On the other hand, this kind of classical studies of reorientation in liquids are required for future development of complete quantum theories incorporating rotational hindering.…”