Fluorescence probe for microenvironments: On the fluorescence properties of p-N,N-dialkylaminobenzylidenemalononitrile in polymer matrices

The effect of an alkyl group (R) in a series of poly(alkylmethacrylate) and poly(alkylacrylate) polymers on the fluorescence properties of p-N,N-dialkylaminobenzylidenemalononitrile derivative, 1, has been studied. The fluorescence emission maximum shifts to the blue and the fluorescence quantum yield decreases as the chain length of R increases. These results are interpreted in terms of a model which assumes that the location of 1 is dependent on R and the change in quantum yield reflects the difference in free volume or polymer chain flexibility in various locations in these polymers.