Boron Substitution in Aluminum Cluster Anions: Magic Clusters and Reactivity with Oxygen
| Autor: | Arthur C. Reber, Shiv N. Khanna, A. W. Castleman, Jordan C. Smith |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry A. 118:8485-8492 |
| ISSN: | 1520-5215 1089-5639 |
| DOI: | 10.1021/jp501934t |
| Popis: | We have studied the size-selective reactivity of AlnBm(-) clusters m = 1,2 with O2 to investigate the effect of congener substitution in energetic aluminum clusters. Mixed-metal clusters offer an additional strategy for tuning the electronic and geometric structure of clusters and by substituting an atom with a congener; we may investigate the effect of structural changes in clusters with similar electronic structures. Using a fast-flow tube mass spectrometer, we formed aluminum boride cluster anions and exposed them to molecular oxygen. We found multiple stable species with Al12B(-) and Al11B2(-) being highly resistant to reactivity with oxygen. These clusters behave in a similar manner as Al13(-), which has previously been found to be stable in oxygen because of its icosahedral geometry and its filled electronic shell. Al13(-) and Al12B(-) have icosahedral structures, while Al11B2(-) forms a distorted icosahedron. All three of these clusters have filled electronic shells, and Al12B(-) has a larger HOMO-LUMO gap due to its compact geometry. Other cluster sizes are investigated, and the structures of the AlnB(-) series are found to have endohedrally doped B atoms, as do many of the AlnB2(-) clusters. The primary etching products are found to be a loss of two Al2O molecules, with boron likely to remain in the cluster. |
| Databáze: | OpenAIRE |
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