Complementary Active Sites Cause Size-Selective Reactivity of Aluminum Cluster Anions with Water
Patrick J. Roach,1
W. Hunter Woodward,1
A. W. Castleman, Jr.,1*
Arthur C. Reber,2
Shiv N. Khanna2
The reactions of metal clusters with small molecules often depend
on cluster size. The selectivity of oxygen reactions with aluminum
cluster anions can be well described within an electronic shell
model; however, not all reactions are subject to the same fundamental
constraints. We observed the size selectivity of aluminum cluster
anion reactions with water, which can be attributed to the dissociative
chemisorption of water at specific surface sites. The reactivity
depends on geometric rather than electronic shell structure.
Identical arrangements of multiple active sites in Al
16–,
Al
17–, and Al
18– result in the production of H
2 from water.
2 Department of Physics, Virginia Commonwealth University, Richmond, VA 23284, USA.
* To whom correspondence should be addressed. E-mail: awc{at}psu.edu
