Electronic properties of substituted aluminum clusters by boron and carbon atoms (Al_nB_m^-/Al_nC_m ^-); 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 Al_n-mB_m^- (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 Al_n^- in Al_nC^- (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.