Observation of electronic shells and characteristic products from mass abundance spectra of Al cluster and Al-C cluster anions

Using a laser vaporization/pulsed molecular beam cluster source, Al cluster anions and Al-C mixed cluster anions are produced and recorded by a time o f flight mass spectrometer. Mass abundance spectra of the Al cluster anions in the size range from Al-2(-) to Al-42(-) show that Al-13(-), Al-23(-) Al -35(-), and slightly, Al-37(-), are local maxims, as predicted by the elect ronic jellium model. Mixed clusters AlnC- and AlnC2- are also shown, among which the most abundant species are Al3C2-, Al6C2-, Al7C- and Al7C2- in the small size range. The formation mechanism of these products is discussed.