Functional macromolecules from single-walled carbon nanotubes: Synthesis and photophysical properties of short single-walled carbon nanotubes functionalised with 9,10-diphenylanthracene

Abstract

9,10-Diphenylanthracene (DPA), a well-studied organic chromophore (Φfl = 0.98) that exhibits electroluminescence, has been covalently bound through 2-(ethylthio)ethylamido linkers to the carboxylic acid groups of short, soluble single-walled carbon nanotubes (sSWNTs) of 1 μm average length, and the resulting DPA-function-alised sSWNT (DPA- sSWNT) macromolecular adducts (4.6 wt % DPA con- tent) characterised by solution 1H NMR, Raman and IR spectroscopy and thermogravimetric analysis. Comparison of the quenching of DPA fluorescence (steady-state and time-resolved) and of the transient optical spectra of sSWNTs and DPA-sSWNTs show that the covalent linkage boosts the interaction between the DPA and the sSWNT units. DPA-sSWNTs exhibit emission in the near-IR region from 1100-1400 nm with an enhanced quantum yield (Φ = 5.7 × 10-3) compared with sSWNTs (Φ = 3.9 Φ10-3). © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.