Rydberg and charge-transfer states of atomic oxygen in Ar and Kr matrices: identification of two distinct sites

Photochemically Induced Energy Transfer II: Spectroscopic and Photophysical Aspects of the Electronic-to-Electronic Energy Transfer in Geminate van der Waals Complexes

“…After partial photolysis at 107 nm, the excitation spectra measured by monitoring the SD emission of O at 560 nm contains not only the broad band at 107 nm due to the 1 Σ u + r X 1 Σ g + transition of CO 2 , but also the A 1 Π r X 1 Σ + vibronic bands of CO between 158 and 130 nm. Additionally, the 3 Sr 3 P Rydberg transition of O at 121.7 nm and the charge transfer transitions of Ar + O -rArO nature between 150 and 125 nm are also seen in the excitation spectra 23 (Figure 2). Thus, photolysis of CO 2 generates not only the geminate O‚‚‚CO van der Waals pair (cage confinement), but also isolated O and CO species (cage exit).…”

“…Broad and blue-shifted SD emission of O from the O‚‚‚CO geminate pair in the SS site is reminiscent of the same emission of O in the tight interstitial site of Ar lattice. 23 Similarly, the sharp 562 nm emission of O from the O‚‚‚CO geminate pair in the DS site resembles highly the SD emission of O from a substitutional site. 23 Thus the above assignment of the two sites of O‚‚‚CO to SS and DS sites is further justified.…”

“…23 Similarly, the sharp 562 nm emission of O from the O‚‚‚CO geminate pair in the DS site resembles highly the SD emission of O from a substitutional site. 23 Thus the above assignment of the two sites of O‚‚‚CO to SS and DS sites is further justified. Spectroscopic Features of the O‚‚‚CO Complex in the SS Site.…”

“…We have followed the photolysis of CO 2 by measuring the ArX vibronic bands of CO monitoring the afX Cameron emission at 215 nm. These spectra shown in Figure 8 reveal that CO 2 is indeed photolyzed efficiently in Kr matrices generating CO. We have also followed the production of O atoms through the excitation spectra of O in Kr by monitoring the SD emission of O at 564 and 600 nm, 23,34 in agreement with the production of CO. Surprisingly, these excitation spectra recorded by monitoring the SD emission of O are dominated by the charge transfer and Rydberg excitation of O in Kr matrices.…”

Charging Effects in an Electron Bombarded Ar Matrix and the Role of Chemiluminescence-Driven Relaxation

“…We now turn our attention to the role of oxygen as a dopant. The photochemistry of oxygen, cage-effect, atom dynamics in matrices and clusters attracted considerable interest [refs − and − and references therein]. The energy transfer from Ar to oxygen centers in Ar clusters of variable size was studied in detail using selective excitation and spectrally resolved emission .…”