Theoretical investigations on the functionalization of carbon nanotubes

In this paper, our recent work concerning theoretical studies on the functionalization of carbon nanotubes (CNTs) is reviewed. In particular, two different aspects of the functionalization process are taken into account. On the one hand, the chemical functionalization of the sidewall is exploited as a way to develop nanostructured gas sensing devices. On the other hand, we investigated the possibility of functionalizing the sidewall with transition metal complexes, thus extending the concepts of organometallic chemistry to CNTs. Calculations were performed by applying statical and dynamical (Car-Parrinello) density functional theory methods, as well as hybrid (quantum mechanics/molecular mechanics) schemes. The structural and electronic peculiarities of the CNT model under study, due, for example to the presence of defects, were found to play a crucial role in the modelization of the functionalization process. In most cases, the use of realistic models was essential to achieve a full agreement with experiments.