Gas-phase photoionization of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)europium(III)

In this Letter, we report observation of fragments of the metal–organic complex, Eu(2,2,6,6-tetramethyl-3,5-heptanedionato)3 resulting from multiphoton ionization of the complex entrained in an Ar molecular beam. Photofragmentation was observed at 532, 355, 266 nm, and in the range of 460–466 nm. At each wavelength, the dominant fragments were bare metal ions in multiple oxidation states and ligand fragments. This fragmentation pattern is interpreted as resulting from excitation to ligand-to-metal charge-transfer states in the sequential ligand dissociation steps. Significantly weaker signal from EuO+ and EuOH+ fragments was also observed with photoionization at 266 nm.