Investigation of Gd3N@C-2n (40 < n < 44) family by Raman and inelastic electron tunneling spectroscopy

The structure and vibrational spectrum of Gd3N@C-80 is studied through Raman and inelastic electron tunneling spectroscopy as well as density-functional theory and universal force field calculations. Hindered rotations, shown by both theory and experiment, indicate the formation of a Gd3N-C-80 bond which reduces the ideal icosahedral symmetry of the C-80 cage. The vibrational modes involving the movement of the encapsulated species are a fingerprint of the interaction between the fullerene cage and the core complex. We present Raman data for the Gd3N@C-2n (40 < n < 44) family as well as Y3N@C-80, Lu3N@C-80, and Y3N@C-88 for comparison. Conductance measurements have been performed on Gd3N@C-80 and reveal a Kondo effect similar to that observed in C-60.