New viologen derivatives having the various para-substituted benzophenone groups connected with a-(CHz) 3-linkage were effectively photoreduced by dimethyl sulfoxide by the intramolecular charge transfer complex formation between the viologen and benzophenone groups through effective stacking. The photoreductim was enhanced by the introduction of electron-donating para-substituents on the benzophenone units which ...
![[4-(3-bromopropyl)phenyl]-(4-nitrophenyl)methanone Structure](https://image.chemsrc.com/caspic/368/142798-88-7.png)