Scandium carbides/cyanides in the boron cage: computational prediction of X@B80 (X = Sc2C2, Sc3C2, Sc3CN and Sc3C2CN).

As the first study on metal carbide/cyanide boron clusterfullerenes, the geometries, energies, stabilities and electronic properties of four novel scandium cluster-containing B80 buckyball derivatives, namely Sc2C2@B80, Sc3C2@B80, Sc3CN@B80 and Sc3C2CN@B80, were investigated by means of density functional theory computations. The rather favorable binding energies, which are very close to those of the experimentally abundant carbon fullerene analogues, suggest a considerable possibility to realize these doped boron clusterfullerenes. Their intracluster and cluster-cage bonding natures were thoroughly revealed by various theoretical approaches. In contrast to carbon clusterfullerenes, in which the encaged non-metal atoms mainly play a stabilizing role in the metal clusters, the encapsulated carbon and nitrogen atoms inside the B80 cage covalently bond to the boron framework, resulting in strong cluster-cage interactions. Furthermore, infrared spectra and (11)B nuclear magnetic resonance spectra were simulated and fingerprint peaks were proposed to assist future experimental characterization.