Photoinduced Formation and Characterization of Electron-Hole Pairs in Azaxanthylium-Derivatized Short Single-Walled Carbon Nanotubes

Autor: Mercedes Alvaro, J. C. Scaiano, Liliana Jimenez, Hermenegildo García, Roberto Martín
Rok vydání: 2009
Předmět:
Zdroj: Chemistry - A European Journal. 15:8751-8759
ISSN: 1521-3765
0947-6539
Popis: 2-Azaxanthone, a nitrogenated derivative of the well-studied organic chromophore xanthone, has been covalently bound through 2-(ethylthio)ethylamido linkers to the carboxylic acid groups of short, soluble single-walled carbon nanotubes (CNTs) of 450 nm average length, and the resulting azaxanthylium-functionalized CNTs (AZX-CNT, 8.5 wt % AZX content) characterized by solution (1)H NMR, Raman and IR spectroscopy and thermogravimetric analysis. Comparison of the quenching of the triplet excited state of AZX (steady-state and time-resolved) and of the transient optical spectra of CNTs and AZX-CNT shows that the covalent linkage boosts the interaction between the azaxanthylium moiety and the short CNT units. The triplet excited state of the azaxanthylium derivative is quenched by CNT with and without covalent bonding, but when it is covalently bonded, the singular transient spectrum is compatible with the photogeneration of electron holes through electron transfer from CNT to excited azaxanthylium units.
Databáze: OpenAIRE
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