Two-Photon Excitation Spectroscopy of Actinyl Ions
The actinyl ion UO 22+in single crystals of CS 2UO 2CI 4is linear and centrosymmetric. Electronic transitions in the region 350-500 nm are parity forbidden by an electric dipole mechanism in single photon absorption spectroscopy. Low temperature, polarized, fluorescence excitation spectra were presented in which the excitation was a pulsed,tunable infrared dye laser operating from 700-1000 nm. Two-photon spectroscopy clearly reveals the presence of 12 “allowed” electronic origins.