Synthesis, Characterization, and Photoinduced Electron Transfer in Functionalized Single Wall Carbon Nanohorns
- 8 March 2007
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 129 (13), 3938-3945
- https://doi.org/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.Keywords
This publication has 28 references indexed in Scilit:
- Preparation, Purification, Characterization, and Cytotoxicity Assessment of Water‐Soluble, Transition‐Metal‐Free Carbon Nanotube AggregatesAngewandte Chemie International Edition, 2006
- Supramolecular Assemblies of Different Carbon Nanotubes for Photoconversion ProcessesAdvanced Materials, 2006
- Cone-End Functionalization of Carbon NanohornsChemistry of Materials, 2006
- Functionalisation of carbon nanohornsChemical Communications, 2006
- Functionalization of Carbon Nanohorns with Azomethine Ylides: Towards Solubility Enhancement and Electron‐Transfer ProcessesSmall, 2006
- Carbon Nanotubes in Electron Donor−Acceptor NanocompositesAccounts of Chemical Research, 2005
- Microporosity Development of Single-Wall Carbon Nanohorn with Chemically Induced Coalescence of the Assembly StructureThe Journal of Physical Chemistry B, 2004
- The Use of Charge Transfer to Enhance the Methane‐Storage Capacity of Single‐Walled, Nanostructured CarbonAdvanced Materials, 2004
- Adsorption Mechanism of Supercritical Hydrogen in Internal and Interstitial Nanospaces of Single-Wall Carbon Nanohorn AssemblyThe Journal of Physical Chemistry B, 2002
- Intramolecular Interaction of Porphyrin Moieties in 2,5-Piperazinedione-Bridged Porphyrin DimersBulletin of the Chemical Society of Japan, 1993