P. Brosset et al., ANALYSIS OF IR ABSORPTION-SPECTRUM OF O-3 IN INERT MATRICES - SPECTROSCOPIC EVIDENCE FOR 2 TRAPPING SITES, Chemical physics, 172(2-3), 1993, pp. 315-324
The infrared spectra of solid O3 and of O3 trapped in rare gas and nit
rogen matrices are analyzed, mainly with O-16(3), a few experiments be
ing performed with O-18-substituted species. The nu3 mode appears as a
doublet except in solid nitrogen. The intensity ratio between the two
components is dependent upon the deposition temperature. This gives e
vidence for two trapping sites. In the nu2 region, the spectrum exhibi
ts a narrow line and a structure of two weaker lines which can be assi
gned to monomeric O3. The two nu3 components show a very different tem
perature dependence: one broadens as soon as 15 K, while the effect is
significant for the second one only at 25 K. The different hypotheses
for the trapping sites are discussed, and the reversible temperature
broadening of the nu3 lines is tentatively explained through a phonon-
assisted vibrational energy transfer from the nu3 mode to the lowest o
ne nu2.