Gas phase atomic association reactions of Ar+, Kr+, and Xe+ at temperatures near 1 K
摘要:
We report the measurement of gas phase three-body atomic ion–atom association reaction rate coefficients at temperatures near 1 K using a free jet flow reactor. The association rate coefficients for the reactions of Ar+ with Ar and Ne, Kr+ with Kr and Ar, and the reactions of Xe+ with Xe, Kr, and Ar have been measured. In all these cases except Ar++Ne, the rate at 1 K is in excess of 9×10−29 cm3/s and a strong negative temperature dependence is observed. These observations are discussed with respect to several microscopic descriptions of the association process.
Photodissociation of Kr<sup>+</sup><sub><i>n</i></sub>clusters
作者:Z. Y. Chen、C. D. Cogley、J. H. Hendricks、B. D. May、A. W. Castleman
DOI:10.1063/1.458854
日期:1990.9
The photodissociation of Kr+n (3≤n≤11) cluster ions is observed for the first time in the 565 to 630 nm wavelength range. Kr+3 has a photodissociation cross section of (8.1±0.8)×10−17 cm2 at 612 nm, while Kr+4 and Kr+5 are found to have larger photodissociation cross sections than Kr+3 with a slightly red-shifted spectrum. Only Kr+ is detected as a photofragment of Kr+3, while in the Kr+n (4≤n≤7) experiments, both Kr+2 and Kr+ photofragments are seen. As size n increases from 7 to 11, Kr+ disappears and Kr+3 appears. Laser power studies show that all are single photon photodissociation processes. For higher order Kr+n clusters (4≤n≤7) the intensity ratio between the two photodissociation products Kr+2 and Kr+ is dependent on the wavelength of the laser light used in the photodissociation, but independent of the polarization direction of the laser. Translational energy analysis of the photofragments is used to investigate the photodissociation mechanisms. In contrast to the photodissociation of Kr+3, where two types of Kr+ photofragments with different values of translational energy release are observed, only one type of Kr+2 photofragment, with zero kinetic energy release is found in the Kr+4 photodissociation. These findings are discussed in terms of the dynamics of photodissociation and possible structures of these cluster ions.
Bogdanova, I. P.; Vladimirov, V. A.; Marusin, V. D., Optics and Spectroscopy, 1989, vol. 66, p. 142 - 144
作者:Bogdanova, I. P.、Vladimirov, V. A.、Marusin, V. D.、Yakovleva, V. I.