The research program involves the synthesis and properties of new types of organic conducting materials. Two main synthetic approaches will be undertaken :
- The synthesis of novel mixed donor (D)/acceptor (A) molecules capable of intramolecular charge transfer (CT);
- The synthesis of molecules containing two units, which after one-electron oxidation give rise to intramolecular CT between the resulting cation-radical moiety (now as an acceptor) and the remaining neutral donor moiety;
- The synthesis of new organofullerenes as strong acceptors.
Expected Outcome

- The project is expected to allow us to gain control over the architectural aspects of the three-dimensional solid state structure, i.e., those structural features that are vital preconditions for electrical conductivity in organic materials. The chemical design requirement is manifested in the construction of molecular units that contains predetermined D-A molecules as well as a degree of charge transfer that may be tuned by appropriate substitution on the D or A moieties.

Results

- New donor and acceptor systems containing nitrogen in the ring have been prepared (1,4-benzoxazine system as the donor fragment) and converted to benzo-TCNQ and benzo-DCNQI adducts. Their electronic spectra and cyclic voltammetry were measured to study their behaviour towards formation new conducting materials.
- The synthesis of the first intramolecular donor-acceptor system that includes a TTF moiety has been carried out. The electrochemical and spectroelectrochemical studies of this new system show that both donor and acceptor moieties keep their identity inside the intramolecular system.
- Fullerene C60was reacted with functionalized o-quinodimethans (i.e. sultines) to form novel organofullerens bearing quinone type adducts as precursors for synthetic metals. Their electrochemistry has been studied which shows them to be potentially electroactive materials that can be used for the preparation of new materials.
- Several novel types of donors with multiple TTF units and halogenated tetrathiafulvalenes were synthesised. Single crystal structures of some of them were determined and their electrochemistry studied. A charge transfer complex of a multiple TTF-unit with TCNQ was prepared and its X-ray structure studied, which revealed a number of unusual features favourable for obtaining high electrical conductivity.
The following project components were defined :
- Preparation of starting quinine derivatives containing nitrogen in the ring as precursors of new D-A, A-D-A and D-A-D systems and their conversion to N,N' dicyanoquinodiimines;
- Synthesis of donors with multiple TTF units and halogenated tetrathiafulvalenes;
- Synthesis of novel donor-acceptor molecules containing efficient donor TTF linked to an efficient acceptor moiety;
- Reaction of fullerene C60 with functionalized o-quinodimethanes to form C60-adducts as strong acceptors.