Nano Archive

Synthesis, characterization, and photoinduced electron transfer in functionalized single wall carbon nanohorns

Cioffi, Carla and Campidelli, Stephane and Sooambar, Chloe and Marcaccio, Massimo and Marcolongo, Gabriele and Meneghetti, Moreno and Paolucci, Demis and Paolucci, Francesco and Ehli, Christian and Rahman, G. M. Aminur and Sgobba, Vito and Guldi, Dirk M. and Prato, Maurizio (2007) Synthesis, characterization, and photoinduced electron transfer in functionalized single wall carbon nanohorns. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 129 (13). pp. 3938-3945.

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL: http://pubs.acs.org/doi/abs/10.1021/ja068007p

Abstract

Single-wall carbon nanohorns (SWNHs) are a new class of material that is closely related to single-wall carbon nanotubes. Here, we describe the synthesis and characterization of a series of SWNHs functionalized with ethylene glycol chains and porphyrins. Functionalization of carbon nanohorns has been achieved using two different synthetic protocols: (1) direct attack of a free amino group on the nanohorn sidewalls (nucleophilic addition) and (2) amidation reaction of the carboxylic functions in oxidized nanohorns. The nanohorn derivatives have been characterized by a combination of several techniques, and the electronic properties of the porphyrin/nanohorn assemblies (SWNH/H2P) have been investigated by electrochemistry, spectroelectrochemistry, and a series of steady-state and time-resolved spectroscopy. The cyclic voltammetry curve of nanohorn/porphyrin conjugate 6 showed a continuum of faradic and pseudocapacitive behavior, which is associated with multiple-electron transfers to and from the SWNHs. Superimposed on such a pseudocapacitive current, the curve also displays three discrete reduction peaks at −2.26, −2.57, and −2.84 V and an oxidation peak at 1.12 V (all attributed to the porphyrin moiety). Steady-state and time-resolved fluorescence demonstrated a quenching of the fluorescence of the porphyrin in SWNH/H2P conjugates 5 and 6 compared to the reference free base porphyrin. Transient absorption spectra permitted the electron-transfer process between the porphyrins and the carbon nanostructures to be highlighted.

Item Type:Article
Subjects:Material Science > Nanofabrication processes and tools
Physical Science > Nano objects
Material Science > Nanochemistry
ID Code:3176
Deposited By:Anuj Seth
Deposited On:26 May 2009 16:58
Last Modified:26 May 2009 16:58

Repository Staff Only: item control page