PHOTOINDUCED FORMATION OF ELECTRON-HOLE PAIRS IN SHORT SINGLE WALL CARBON NANOTUBES (sSWNT)

LILIANA B. JIMENEZ; ROBERTO MARTIN; HERMENEGILDO GARCIA; J. C. SCAIANO

Ottawa, Canada

Simposio; 36th Physical Organic Mini Symposium (POMS); 2008

Short Single Wall Carbon Nanotubes (sSWNT) have been the focus of considerable attention in the last years for their promising physical and electrical properties. Furthermore, covalent functionalization of sSWNT has been used extensively to modify some of these properties. It has been reported that depending on the partner introduced to carbon nanotubes they act as electron donors or electron acceptors. The ability to respond to an external stimulus, particularly electronic excitation, is a highly desirable property that could generate functional materials such as sensors, relays, photovoltaic and, in general, nano-devices.In this work, we present covalently linked sSWNT to 2-azaxanthone (AZX-t-sSWNT) as a simple system, which is able to generate electron-hole pairs efficiently upon UV exposure. Azaxanthone (AZX-t) was chosen because, as most of aromatic ketones, it is a good electron acceptor and undergoes efficient charge-transfer interactions with pi-systems. Moreover, the triplet excited state of AZX-t can be monitored using laser flash photolysis. In contrast with the monomeric structure, AZX-t-sSWNT shows a very short AZX triplet lifetime indicating a clearly interaction with the nanotube and, as a consequence, leading to efficient triplet quenching.