Observation of Electronic shells and Characteristic Products from Mass Abundance Spectra of AI Cluster and AI-C Cluster Anions

Using a laser vaporization/pulsed molecular beam cluster source, AI cluster anions and A1-C mixed cluster anions are produced and recorded by a time of flight mass spectrometer. Mass abundance spectra of the AI cluster anions in the size range from AI^-₂ to AI^-₄₂ show that AI^-₁₃, AI^-₂₃, AI^-₃₅, and slightly, AI^-₃₇ are local maxima, as predicted by the electronic jellium model. Mixed cluster AI_nC^- and AI_nC^-₂ are also shown, among which the most abundant species are AI₃C^-₂, AI₆C^-₂,AI₇C^- and AI₇C^-₂in the small size range. The formation mechanism of these products is discussed.