Mixed Metal Nitride Clusterfullerenes in Cage Isomers: LuxSc3-xN@C80 (x=1, 2) As Compared with MxSc3-xN@C80 (M = Er, Dy, Gd, Nd)

Two isomers of lutetium-scandium mixed metal nitride clusterfullerenes (MMNCFs), LuxSc3-xN@C-80 (x = 1, 2), have been synthesized and isolated for the first time, and accordingly, the interplay of the cluster structure and cage isomerism is followed. The electronic and vibrational properties of LuxSc3-xN@C-80 (I, II, x = 1, 2) are characterized by UV-vis-NIR and FTIR spectroscopies, revealing the effect of the composition of the encaged LuxSc3-xN cluster. A comparative study of LuxSc3-xN@C-80 (1) with other MxSc3-xN@C-80 (I; M = Er, Dy, Gd, Nd) MMNCFs points to the dependence of their electronic and vibrational properties on the encaged metal. The cage structures of LuxSc3-xN@C-80 (I, II; x = 1, 2) are determined by C-13 NMR spectroscopy. The Sc-45 NMR spectroscopic study is carried out to probe the dynamics of the encaged Sc atoms. Finally, DFT computations are used to address the effect of the composition of the encaged LuxSc3-xN cluster on the NMR lines and the structures of LuxSc3-xN@C-80 (I, II; x = 1, 2) especially with respect to the carbon atoms.