Single-wall carbon nanotube porphyrin nanoconjugates

Abstract

We describe the synthesis, microscopic and spectroscopic characterization of a novel donor-acceptor prototype, namely, a single wall carbon nanotube (SWNT) nanoconjugate bearing a covalently linked free base porphyrin ( H 2 P ). In the characterized SWNT- H 2 P nanoconjugate the electronic features of SWNT are largely retained, when compared to pristine SWNT. In fact, carefully controlled reaction conditions lead to a low degree of SWNT functionalization, as evidenced by the preservation of the SWNT van Hove singularities. As a consequence, the overall SWNT loading with H 2 P is so low that in the ground state, the H 2 P features are barely seen, which is different from the excited state, where features of H 2 P are clearly discernable. For example, fluorescence and transient absorption characteristics corroborate, unequivocally, the formation of the H 2 P singlet excited state, which is, however, impacted by the presence of SWNT.