Preparation of polyimide Langmuir-Blodgett films containing [Ru(bpy) 3] 2+ complex

Abstract

The preparation of polyimide Langmuir-Blodgett (LB) films containing [Ru(bpy) 3] 2+ (bpy ≡ 2,2'-bipyridine) is described. Newly synthesized [Ru(5,5'-diamino-bpy)(bpy) 2] 2+ was found to undergo a direct polymerization reaction with acid dianhydrides, which affords the corresponding polyamic acids (potential precursors of polyimide LB films). For LB film deposition, the copolymerization approach using flexible 4,4'-diaminodiphenyl ether was adopted, because of the insufficient stability of a monolayer of the polyamic acid long alkyl amine salt from only [Ru(5,5'-diamino ≡ bpy) (byp) 2] 2+. Thus obtained polyamic acid LB films using 1,2,3,4,-cyclobutanetetrarboxylic dianhydride were finally converted into the polyimide LB films containing [Ru(bpy) 3] 2+. The photoelectrochemical characteristics of the polyimide LB films on indium tin oxide electrodes were also studied.