Exohedral complexes of large fullerenes, a theoretical approach.

The possibility of existence of exohedral organometallic complexes of fullerenes larger than C60 in which their coordination can have η6 hapticity was studied from a theoretical point of view. Complexes containing C70, C74 or C60 cages, as well as cyclopentadienyl (Cp), pentamethyl-cyclopentadienyl (Me5Cp), benzene rings and hexamethyl-phenyl (Me6Ph) fragments as ligands, were designed and studied. The results show that many of these molecules can be thermodynamically stable and can have electronic interesting behavior.

On the π coordination of organometallic fullerene complexes.

Novel organometallic complexes of fullerene C80 and aryl ligands were simulated. The nature and characteristics of this family of complexes involving π coordination between the fullerene and a metal centre have been studied from a theoretical point of view. We are particularly interested in complexes where η6 coordination is present, this being the strangest manifestation of known coordinations, and thus we have studied several known and simulated compounds of this kind in order to understand the lack of examples. The presence of other η6 or η5 ligands on the opposite side seems to be an important element aiding the stabilization of these complexes, also inducing the conductive and semiconductive behaviour of the studied species.

Aromaticity in cyanuric acid.

This study analyzes the aromatic nature of cyanuric acid (hexahydrotriazine) and some of its derivatives, in terms of aromatic stabilization energy (ASE) and electronic behavior. The simplest molecule (C(3)N(3)O(3)H(3)) is the most aromatic item out of the entire set, but some of the others also display aromatic character. The structure of all the rings is analyzed considering their molecular orbitals as well as studying the inductive effect.