Backbone planarity effects on triplet energies and electron-electron correlation in luminescent conjugated polymers

A general survey of triplet energies and lifetimes of conjugated organic polymers, measured in solution by pulse radiolysis triplet energy transfer, is made to determine if any general correlations to the morphology of each conjugated backbone exist. Two trends are apparent, firstly backbone rigidity has a large influence on electron-electron correlation energy and secondly steric torsion between neighbouring repeat units, which controls effective conjugation length, influences both triplet energy and triplet lifetime. The latter, though, is controlled more by the degree of spin orbit coupling on the backbone. (C) 2003 Elsevier B.V. All rights reserved.