ALPHA,ALPHA-DINAPHTHYLPROPANE - A MODEL FOR POLYMER PHOTOPHYSICS AND A PROBE FOR THE INVESTIGATION OF MACROMOLECULAR DYNAMICS

The time-resolved photophysical behaviour of alpha,alpha-dinaphthylpro pane (alphaalpha-DNP) in iso-octane solution at temperatures greater t han 30-degrees-C is in good agreement with the predictions of Birks ki netics. At temperatures below 30-degrees-C the fluorescence decay beha viour is more complex. This has serious implications for the attempted use of alphaalpha-DNP (or indeed any other bichromophoric compound) i n attempts to probe macromolecular dynamics if 'forced fits' to dual-e xponential functions were to be employed. The complexity of the fluore scence decay behaviour of such a simple model molecule (in which the c omplication of 'tacticity' and/or energy migration effects are obviate d) has implications regarding the interpretation of the photphyiscal b ehaviour of macromolecules derived from vinyl aromatic monomers.