PHOTOPHYSICS OF PYRENE SUBSTITUTED OLIGOSILANES

The absorption and fluorescence properties of 1-pyrenyl substituted pe rmethyloligosilanes are reported. The charge transfer in 1-pyrenyltrid ecamethylhexasilane is explained by electron transfer from the Si-Si s igma orbitals to pyrene in the excited state. Evidence is found for gr ound state interactions in 1,3-di(1-pyrenyl)hexamethyltrisilane, based on absorption and H-1-NMR measurements. The fluorescence properties o f 1-(1-pyrenyl), 3-(p-N,N-dimethylanilino)hexamethyltrisilane are comp ared with its carbon analogue 1-(1-pyrenyl), 3-(p-N,N-dimethylanilino) propane. Ground state interactions are found for the silicon-bridged d onor-acceptor compound.