A DFT study of methylamine polyaddition to C80 fullerene

We studied theoretically (GGA PW91 density functional theory in conjunction with the double-numerical basis set) the C-80 functionalization by methylamine through successive reactions with up to three methylamine molecules. We calculated the energies of formation (relative to the level of separated reactants) of different isomers and, in accordance with these values, we defined the most probable site of reaction in each addition. The preferred addition sites are carbon atoms of the 5,6 bonds of the five-membered ring next to the pentagon of the previous addition. The pyramidalization angle theta(p) can explain the reactivity of C atoms in pristine C-80, but not in the amine-functionalized C-80. At the same time, the higher reactivity is generally associated with shorter 5,6 C=C bond lengths. (C) 2008 Elsevier Ltd. All rights reserved.