UV photochemistry of trivinylantimony adsorbed on quartz

Abstract

The surface photochemistry of trivinylantimony adsorbed on a cold quartz surface was investigated using pulsed 193 nm excimer-laser radiation. The major desorption products observed were C 2H 2, C 2H 3, C 2H 4, C 4H 6, Sb, Sb(C 2H 3), Sb(C 2H 3) 2, Sb(C 2H 3) 3 and Sb 2. Photoproduct distributions and their Maxwell-Boltzmann characteristic temperatures were determined using time-of-flight mass spectrometry, incorporating both electron impact and, for Sb detection, resonance-enhanced multiphoton ionization. Photoproduct yields and Maxwell-Boltzmann temperatures were dependent on photon fluence, sample dosage and surface temperature. The Maxwell-Boltzmann temperatures of the C x H y , products were substantially lower than those of the metallic and organometallic species, indicating that the desorption of the Sb-containing products probably occurs via electronically excited states. A mechanism is given for the photochemistry of adsorbed trivinylantimony.