PHOTOCHEMICAL BEHAVIOR AND EMISSION CHARACTERISTICS OF 9-VINYLANTHRACENE

9-Vinylanthracene (9-VA) is an efficient fluorescer of fluorescence quantum yield .vphi.f = 0.91 .+-. 0.03 in methanol (.lambda.ex=365 nm). This is consistent with its low photochemical quantum yields .vphi.c (.lambda.ex = 365 nm) of 0.005 in the absence of azobisisobutyronitrile (AIBN) radical initiator and .vphi.c=0.02 in the presence of 10-2 M dm-3 AIBN. 9-Vinylanthracene was shown to behave as a 9-substituted anthracene undergoing photodimerization rather than the typical vinyl aryl monomer photopolymerization. The photodimer formation is supported by spectroscopic techniques. 9-Vinylanthracene undergoes efficient fluorescence quenching in the presence of AIBN. Stern-Volmer plots indicate a collisional mechanism. 9-Vinylanthracene crystals as well as polycrystalline films give excimeric emission (.lambda.max=510 nm, .lambda.ex=380 nm) which is considerably red shifted (ca. 100 nm) compared with molecular emission.