Gwion Williams

Spectroelectrochemical and electrical characterization of low bandgap polymers

Abstract In situ FT-IR spectroscopy, and d.c. and a.c. electrical measurements were used to characterize an electronically conducting polymer prepared from the electropolymerization of a bridged dithienyl monomer. Electronic absorption bands were observed during both n- and p- doping processes. The solid state data showed that the metal|polymer|metal diodes displayed no rectification although capacitance and loss data showed a strong frequency dispersion characteristic of a Schottky diode.

The study of conducting polymers for use as redox supercapacitors

Abstract Electronically conducting polymers have been prepared from bridged dithienyl derived monomers. These monomers have been designed in order to yield polymers that possess a low bandgap (c.a. 1 eV). Recently low bandgap polymers have been targeted for use as the active material in electrochemical capacitors, better known as Supercapacitors. We report the characterisation of these polymers using cyclic voltammetry, electrochemical impedance spectroscopy and discharge cycles.

Synthesis, electrochemical properties and electropolymerization studies on 3-thienyl substituted tetrathiafulvalenes. Single-crystal X-ray structure of 4,4′,5,5′-tetrakis-(3-thienyl)-tetrathiafulvalene

Abstract The synthesis and solution electrochemical properties of two novel 3-thienyl substituted tetrathiafulvalene (TTF) donors 7 and 11 are described. The single-crystal X-ray structure of 7 is reported, which is characterized by the presence of short intermolecular SS contacts. Cyclic voltammetry of the derivatives indicates that two reversible redox waves, characteristic of TTF derivatives, are present. Attempts were made to electropolymerize the two derivatives at a platinum electrode in dichloromethane. Formation of a blue-coloured solid, characteristic of the thiophene radical cation species, was observed for one of the derivatives, but it was not possible to isolate a polymer on the working electrode. Preliminary electropolymerization studies on the TTF ‘half unit’ 6 are also reported.

4,4′,5,5′-Tetrakis(2-thienyl)tetrathiafulvalene [TT-TTF]: synthesis and first X-ray crystal structure of a thiophene-substituted TTF electron donor

The synthesis, electrochemical properties, preliminary electropolymerisation studies and the single-crystal X-ray crystal structure of the title compound 1 (TT-TTF), a novel thiophene-substituted tetrathiafulvalene electron donor, are described.

Spectroelectrochemistry of bridged dithienyl derived polymers

Low bandgap conducting polymers have been prepared from the electropolymerisation of bridged dithienyl derived monomers. These low bandgap polymers undergo redox switching from neutral to doped states, the switching is accompanied by changes in the optical properties of the polymers. We report the characterisation of these polymers using cyclic voltammetry, in situ UV and FTIR.