Eur. Phys. J. D (2013) 67: 80
https://doi.org/10.1140/epjd/e2013-30677-5

Regular Article

Size-dependent reactivity of aluminum cluster cations toward water molecules^*

Department of Chemistry, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, 812-8581 Fukuoka, Japan

^a e-mail: terasaki@chem.kyushu-univ.jp

Received: 6 November 2012
Received in final form: 7 February 2013
Published online: 30 April 2013

Abstract

We present gas-phase reaction of size-selected aluminum cluster cations (Al_N⁺ , N = 3–19) with a water molecule. As major reaction products, Al_NO⁺ and Al_N(H₂O)⁺ were observed for N ≥ 6 under single-collision conditions. The production of Al_NO⁺ implies that Al_N⁺ reacts with a H₂O molecule to form Al_NO⁺ and H₂. In contrast to the previous report on H₂ generation by Al_N^-, a wider size range of Al_N⁺ exhibited high reactivity via a different mechanism. Selective formation of either Al_NO⁺ or Al_N(H₂O)⁺ was observed in the size range of 6 ≤ N ≤ 13. Our results suggest that the internal energy of a precursor complex [Al_N(H₂O)⁺]^∗ is relevant to the selectivity of the reaction products.