Picture of wind turbine against blue sky

Open Access research with a real impact...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs.

The Energy Systems Research Unit (ESRU) within Strathclyde's Department of Mechanical and Aerospace Engineering is producing Open Access research that can help society deploy and optimise renewable energy systems, such as wind turbine technology.

Explore wind turbine research in Strathprints

Explore all of Strathclyde's Open Access research content

Synthesis and properties of monodisperse oligofluorene-functionalized truxenes : highly fluorescent star-shaped architectures

Kanibolotsky, A.L. and Berridge, R. and Skabara, P.J. and Perepichka, I.F. and Bradley, D.D.C. and Koeberg, M. (2004) Synthesis and properties of monodisperse oligofluorene-functionalized truxenes : highly fluorescent star-shaped architectures. Journal of the American Chemical Society, 126 (42). pp. 13695-13702. ISSN 0002-7863

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

This paper describes the strategy toward novel monodisperse, well-defined, star-shaped oligofluorenes with a central truxene core and from monofluorene to quaterfluorene arms. Introduction of solubilizing n-hexyl groups at both fluorene and truxene moieties results in highly soluble, intrinsically two-dimensional nanosized macromolecules T1-T4. The radius for the largest oligomer of ca. 3.9 nm represents one of the largest known star-shaped conjugated systems. Cyclic voltammetry experiments reveal reversible or quasi-reversible oxidation and reduction processes (E-ox = +0.74 to 0.80 V, E-red = -2.66 to 2.80 eV vs Fc/Fc(+)), demonstrating excellent electrochemical stability toward both p- and n-doping, while the band gaps of the oligomers are quite high (E-g(CV) = 3.20-3.40 eV). Close band gaps of 3.05-3.29 eV have been estimated from the electron absorption spectra. These star-shaped macromolecules demonstrate good thermal stability (up to 400-420 degreesC) and improved glass transition temperatures with an increase in length of the oligofluorene arms (from T-g = 63 degreesC for T1 to 116 degreesC for T4) and show very efficient blue photoluminescence (lambda(PL) = 398-422 nm) in both solution (Phi(PL) = 70-86%) and solid state (PhiPL = 43-60%). Spectroelectrochernical experiments reveal that compounds T1-T4 are stable electrochromic systems which change their color reversibly from colorless in the neutral state (similar to340-400 nm) to colored (from red to purple color; similar to500-600 nm) in the oxidized state.