J Phys Chem Lett. 2012 May 17;3(10):1363-8. doi: 10.1021/jz3004427. Epub 2012 May 07.

Photochemistry of a Model Cationic p-Phenylene Ethynylene in Water.

The journal of physical chemistry letters

Eric H Hill, Subhadip Goswami, Deborah G Evans, Kirk S Schanze, David G Whitten

PMID: 26697924 DOI: 10.1021/jz3004427

Abstract

One important aspect of p-phenylene-ethynylenes that has not yet been explored is the possible photochemical reactions that can take place in different chemical environments. This is especially important when considering the possible breakdown of these compounds in applications that involve exposure to light, air, and water. In this Letter, a study of the photochemical reaction processes of a cationic oligomer based on the p-phenylene-ethynylene repeat unit is performed in aqueous solution in both the presence and absence of oxygen. Clearly different reaction pathways were observed in the presence and absence of oxygen in aqueous solution. The results of this study revealed the photoaddition of water across the triple bond of the ethynyl group in the absence of oxygen, the addition of singlet-oxygen across the triple-bond in the presence of oxygen, and the cleavage of the alkoxy side chains leaving phenols in both cases.

Keywords: OPE; antimicrobial polymers; cationic side chains; oligo-phenylene-ethynylene; organic light-emitting diodes; phenyl ether cleavage; phenylacetylene; photoreaction in water

Publication Types

• Journal Article
• Research Support, U.S. Gov't, Non-P.H.S.