Linear aluminum- and phosphorus-doped carbon cluster anions: Mass distribution and ab initio calculations

Abstract

Both aluminum- and phosphorus-doped carbon cluster anions were produced by laser ablation on mixed powder samples. Dramatic even/odd alternation of the cluster ion signal intensity can be observed in their recorded mass spectra. The mass distributions reveal that the C n Al − clusters with even n are more stable than those with odd n, while the C n P − clusters with odd n are more stable than those with even n. The contrary parity effects are confirmed by ab initio Hartree–Fock calculations carried out on a linear cluster model. Calculated energies, which are expressed as the energy difference between the adjacent clusters as well as the binding energy and the electron binding energy, and optimized geometries of the clusters also favor the singlet species, which are the C n Al − clusters with even n and the C n P − clusters with odd n.