Room temperature and low-temperature absorption and emission spectra of some polypyridylruthenium(II) 3.2.1 complexes

Electronic absorption and luminescence spectra are reported for a series of complexes of type [Ru(tpy)(L-L)(py)](2+), where tpy and py are 2,2 ' ,2 " -terpyridine and pyridine, and L-L represents the bidentate ligands bipyrid yl, 4,4 ' -dimethylbipyridyl. 4-nitrobipyridyl, oxalate and acetylacetonate . The effect of solvent polarity and temperature on their spectral and ligh t emission properties is studied. Energies are reported for the lowest-ener gy (MLCT)-M-3* excited state, and on the basis of these it is suggested tha t the complexes may make good triplet energy accepters for use in organic a nd polymeric light emitting devices. (C) 2001 Elsevier Science B.V. All rig hts reserved.