JILA and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309, USA.
J Chem Phys. 2013 Aug 14;139(6):064315. doi: 10.1063/1.4817664.
Photodissociation of ICN(-)(CO2)n, n = 0-18, with 500-nm excitation is investigated using a dual time-of-flight mass spectrometer. Photoabsorption to the (2)Π(1/2) state is detected using ionic-photoproduct action spectroscopy; the maximum absorption occurs around 490 nm. Ionic-photoproduct distributions were determined for ICN(-)(CO2)n at 500 nm. Following photodissociation of bare ICN(-) via 430-650 nm excitation, a small fraction of CN(-) is produced, suggesting that nonadiabatic effects play a role in the photodissociation of this simple anion. Electronic structure calculations, carried out at the MR-SO-CISD level of theory, were used to evaluate the potential-energy surfaces for the ground and excited states of ICN(-). Analysis of the electronic structure supports the presence of nonadiabatic effects in the photodissociation dynamics. For n ≥ 2, the major ionic photoproduct has a mass corresponding to either partially solvated CN(-) or partially solvated NCCO2.
用双飞行时间质谱仪研究了 500nm 激发下 ICN(-)(CO2)n(n=0-18)的光解。通过离子产物作用光谱检测到（2）Π(1/2)态的光吸收；最大吸收出现在 490nm 左右。在 500nm 处测定了 ICN(-)(CO2)n 的离子产物分布。在 430-650nm 激发下裸 ICN(-)光解后，产生少量的 CN(-)，表明非绝热效应对这种简单阴离子的光解起作用。在 MR-SO-CISD 理论水平上进行的电子结构计算用于评估 ICN(-)的基态和激发态的势能面。电子结构分析支持光解动力学中存在非绝热效应。对于 n≥2，主要的离子产物的质量对应于部分溶剂化的 CN(-)或部分溶剂化的NCCO2。
