p-Phenylenediacrylic acid (p-PDA) displays excimeric emission in concentrated solutions (concentration ca. 0.5 M) in dimethylsulphoxide (DMSO). The excimeric
emission maximum is red shifted by ca. 5200 cm–1 compared with molecular emission
maximum. The fluorescence quantum yields of p-PDA has been measured in DMSO
(φf = 0.09, λex = 337 nm) and in cetyltrimethylammonium chloride (CTAC) cationic
micelles that show remarkable solubilization of p-PDA.The solution photoreactivity of p-PDA is wavelength dependent. In dilute DMSO
solutions, 365 nm and 310 nm light causes p-PDA consumption giving a photoproduct
of maximum absorption at ca. 265 n,. A back photoreaction is induced by 254 nm light.
The photochemical quantum yields (φc) of the forward photochemical reaction have
been measured as a function of temperature and the activation energy was evaluated
as Ea = 9 kJ mol–1 suggesting a unimolecular photoisomerization process.Emission from crystalline p-PDA has also been reported. The emission maximum is
red shifted from molecular emission maximum by ca. 3250 cm–1.The energy transfer in the system diethyl-p-phenylenediacrylate (p-PDAEt)-1,4-bis(β-pyridyl-2-vinyl)benzene(P2VB) has been studied. Triplet states formation mechanism
is proposed.
