Research in the area of conjugated polymers has attracted significant interest recently in view of their exciting prospects for applications in electronic devices.  An important area is concerned with development of materials for opto-electronic uses, and the past decade has seen the development of a range of conjugated polymers with great promise for application in polymer based light emitting diodes (PLEDs) and solar cells.

 

We have developed two families of carbazole main chain conjugated polymers in which the carbazole repeat units are linked either through the 2,7-positions, poly(9-alkylcarbazole-2,7-diyl)s (structure A, scheme 1) or the 3,6-positions, poly(9-alkylcarbazole-3,6-diyl)s (structure B, scheme 1).

Studies have shown that poly(9-alkylcarbazole-2,7-diyl)s A exhibit more favorable properties in comparison with their poly(9-alkylcarbazole-3,6-diyl)s B analogues.  However, poly(9-alkylcarbazole-2,7-diyl)s have been shown to be unstable under electrolytic conditions. This could be attributed to the formation of new linkages between the 3,6-positions of adjacent polymer chains within the films.  

In this work, we will present our results on the preparation, characterisation and investigation of the photophysical properties of 2,7-linked 9-alkyl-carbazole polymers and copolymers (structures C, scheme 1) where the 3,6-positions have been substituted with methyl groups in order to prevent cross-linking side reactions.

 

Acknowledgements

We wish to thank EPSRC for financial support of this work.