Photofragmentation Pathways and Photodeposition of Nanoparticles from a Gas Phase Copper-Containing Precursor

Pulsed laser excitation of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) (Cu(TMHD)2) in the gas phase produced neutral gaseous copper atoms and nanoparticulate copper deposits on substrates. Copper atoms were formed by the complete dissociation of the ligands from the metal. Time of flight mass spectrometry and resonance enhanced multiphoton ionization spectroscopy were used to study the details of this reaction and led to the discovery of other gaseous fragments that were produced by incomplete fragmentation of the ligands including monoligated species and coordinated ligand fragments. Laser-assisted chemical vapor deposition resulted in monodispersed nanoparticles under 100 nm in diameter. X-ray photoelectron spectroscopy and energy dispersive analysis of X-rays were used to determine the elemental composition of the deposit. The relationships between the photofragmentation pathways and the deposited particles are discussed.