PURPOSE: To efficiently reduce a viologen derivative having a photosensitizing benzophenone structure bonded to a viologen skeleton by using visible light or a chemical reducing agent.
CONSTITUTION: A viologen derivative of formula I (X is Cl or ClO4) can be reduced in high efficiency by using visible light or a chemical reducing agent. For example, 1mol of the viologen derivative of formula I is dissolved in 106 to 103mol of a solvent containing 1-100% of a reducing agent and irradiated with a UV-cut xenon lamp for 10min to 3hr. As an alternative, the viologen derivative of formula 1 is reduced by adding 1-5 equivalent of a chemical reducing agent (e.g. metallic sodium or sodium dithionite) to l equivalent of the compound of formula I. A one-electron reduction product of formula II can be produced by this process. Since reduction product of viologens has clear color, it can be applied to photosensitive material, electro-sensitive display material, oxidation-reduction mediator and various sensors.
NANBU YOKO
ENDO TAKESHI
