UV-VIS, IR and Raman investigations have been carried out on purified LiCa Cho produced by low energy ion implantation of C-60. Two endohedral fractions can be isolated that have very different optical properties and stabilities. Here we show that the first endohedral fraction is a dimer species and the second fraction is the monomer. The IR spectra of sublimed monomer films show a prominent peak at around 1.1 mum corresponding to the first electronic transition of the C60 anion. Raman spectra show the vibrational-rotational movement of the Li inside the carbon cage. (C) 2002 Elsevier Science B.V. All rights reserved.