Enhanced stability of the NbO and NbO clusters: the π rule superatomic nature.

This study examines the chemical reactivity of niobium clusters with carbon dioxide (CO), with an emphasis on the analysis of the ensuing products NbO and NbO, which show up in the cationic and anionic mass spectra, respectively. Using density functional theory (DFT) calculations, we demonstrate the reactivity of the Nb clusters with CO and reveal distinct stabilization mechanisms for the two prominent products. The stability of NbO is determined by the existence of ten π bonds pertaining to π-electron delocalization, which conforms to the π electron configuration model. Despite having only a one-atom distinction, NbO exhibits superatomic electron shells embodying superatom stability. The divergent stabilizing mechanisms found in NbO and NbO illustrate the intricate nature of cluster chemistry and the significance of electronic structure in governing cluster stability and reactivity.