A laser spectroscopic study of the Ni–Kr complex

Abstract

Electronic transitions of the Ni–Kr complex have been studied by a photolysis–supersonic jet experiment. The Ni atom is generated by the photolysis of nickelocene, Ni(C₅H₅)₂, and the complex is formed by coexpansion with Kr or Kr in He. Two new bands are observed at similar wavelength regions to those of Ni–Ar, and they are attributed to the electronic transitions of Ni–Kr. The structure of these bands are analyzed as vibrational progressions, which provide binding energies for two excited states of Ni–Kr, D₀^′ = 81 cm⁻¹ and 160 cm⁻¹, respectively. They are a little larger than those of Ni–Ar, as expected from the larger dispersive interaction of Kr than Ar with Ni. Since dispersed fluorescence of these bands consists of entirely atomic transitions of Ni, the excited states of the Ni–Kr complex is considered to predissociate to Ni* + Kr with very short lifetimes. Two excited states, Ni(³F₃ and z¹P₁), are selectively formed from the excitation of one band system and several states of Ni are formed from the excitation of the other system. These products are explained by potential curve crossings ia spin–orbit interaction. Asymptotic limits for the upper states of these bands are proposed to be Ni(y ³D₁) + Kr and Ni(y³D₂) + Kr, respectively.