A metastable state of CO in Ar matrix at about 11 eV

Photochemically Induced Electronic-To-Electronic Energy Transfer in Geminate CO···O van der Waals Pair Generated through Vacuum Ultraviolet Photolysis of CO2 in Ar Matrices

“…The excitation spectrum (Figure a) measured by monitoring the emission at 714 nm is identical with the corresponding spectrum shown in Figure a, indicating that in both the cases, the spectra result from isolated CO. At 510 nm both CO and O 2 show emission. Observation of the excitation bands of CO with v ‘ > 3 by monitoring the 510 nm emission is consistent with the observations of Bahrdt and Schwentner 34c. From these results we can confidently conclude that in matrices containing CO and O 2 at high dilution, no energy transfer of any kind takes place when excited between 200 and 100 nm.…”

“…After the photolysis, excitation bands due to CO (157−130 nm) and due to O (133 and 121 nm) can clearly be identified. Excitation spectra of CO in rare-gas matrices are thoroughly investigated by Schwentner and co-workers, , which will be referred to at a later point in this article. Excitation bands at 130 and 121 nm due to O in Ar matrices were identified by us in our earlier investigations …”

“…Schwentner and co-workers 34,35 thoroughly investigated the spectroscopic properties of CO in rare-gas matrices. However, the A 1 Π ← X 1 Σ + transition of CO only in Ne matrices has been published by these authors 34c. The data pertinent to other matrices (Ar and Kr) can be found in the doctoral thesis of Bahrdt .…”

“…Our excitation spectrum differs from that of Taylor et al We observe unresolved bands as also found by Taylor et al, but the vibrational spacing of ∼1200 cm -1 is significantly different from 687 cm -1 reported by them. Interpretation of the spectra of CO 2 is further complicated by the excitation bands between 117 and 100 nm of the photoproduct CO due to B ← X, C ← X, and E ← X transitions 34d. Further experimental and theoretical investigations on CO 2 and its isotopomers are necessary in order to clarify these differences and get more information on the spectroscopic properties of CO 2 in matrices.…”

Interaction of a magnetic field with the a′3Σ+–A1Π complex in CO

“…Beyond the present work let us mention the possibility of a rotationally resolved detection of the CO quintet state aЉ 5 ⌸ at about 11 eV. 20,21 The idea is to use the triplet state aЈ 3 ⌺ ϩ as an intermediate level from which the aЉ 5 ⌸ state will be reached in a second intercombination transition. This latter step improves with increasing population density N a Ј .…”