Danny Halla, Andrew F. Parsonsa and Derek Irvineb a Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK. b Uniqema, Wilton Centre, Wilton, Redcar, TS10 4RF, UK.

This project focuses on the application of chain initiating/capping molecules in alkene polymerisations. Such molecules can provide a means of controlling the polymerisation and the characteristics of the product. Of particular interest are reactions that lead to the inclusion of functional groups within the polymer chain, particularly if this leads to useful product characteristics or the ability to add desirable functionality at a later stage. Synthesis of novel initiating/capping molecules is an integral part of this research. An example of a capping reaction is shown below using 2,3-dibromopropene.

The use of metals in organic synthesis is widespread. Examples of halogen atom abstraction by metals is well documented using methodologies such as tin chemistry. This project will study the effects of various manganese complexes as halogen atom abstracting agents. Generally this is achieved by creation of a manganese-centred radical which goes on to abstract the halogen atom, forming a strong manganese-halide bond. This will generate an initiating species to begin a polymerisation sequence.

The optimisation of the manganese reaction system and initiating/capping mechanism form the basis of future work in this area. By combining the manganese complex with the capping species, it is possible to synthesise novel polymers using a controlled polymerisation. The range of functionality available in the initiating/capping species can allow the production of telechelic species which could be used to provide specific application properties or sites for further reaction. This makes these techniques a useful new tool in polymer chemistry and organic synthesis as a whole.

© Department of Chemistry, University of York.