Electronic properties of substituted aluminum clusters by boron and carbon atoms (AlnBm−/AlnCm−); new insights into s–p hybridization and perturbed shell structures

Substituted Al clusters with B atom, which is trivalent but smaller than Al atom, or with covalent C atom were investigated using photoelectron spectroscopy (PES). In Aln−mBm− (n⩾5 for m=1, n⩾10 for m=2), three valence electrons of each B atom as well as Al atom contribute to electron shell structures, while the C atom strongly binds two free electrons from Aln− in AlnC− (n=5–30). The substitution with B atom allowed us to determine that s–p mixing starts at n=6 in pure Al clusters. Perturbed electron shells and the geometry of Al12B1−, Al11B2−, and Al12C− are discussed.