Endohedral Ca@B38: stabilization of a B382− borospherene dianion by metal encapsulation

Based on extensive global-minimum searches and first-principles electronic structure calculations, we present the viability of an endohedral metalloborospherene Cs Ca@B38 (1) which contains a Cs B382− (2) dianion composed of interwoven boron double chains with a σ + π double delocalization bonding pattern, extending the Bnq (q = n − 40) borospherene family from n = 39–42 to n = 38. Transition metal endohedral complexes Cs M@B38 (M = Sc, Y, Ti) (3, 5, 7) based on Cs B382− (2) are also predicted.