Table of Contents
Laser Chemistry
Volume 5 (1985), Issue 5, Pages 309-319

Excimeric Emission and Photochemical Behavior of p-Phenylenediacrylic Acid (p-PDA) and its Diethyl-Ester (p-PDAEt)

1Chem. Dept., Faculty of Science, Tanta Univ., Tanta, Egypt
2Faculty of Engineering, The University of Tokyo, Hongo, Bunkyo-Ku, Tokyo 113, Japan

Received 15 July 1985

Copyright © 1985 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.