Organic Mixed Valence Systems. II. Two-Centers and Three-Centers Compounds with Meta Connections around a Central Phenylene Ring

Abstract

This paper is devoted to two new aromatic polyamines derived from p-EFTP (5‘-(4-(bis(4-ethylphenyl)amino)phenyl)-N,N,N‘,N‘-tetrakis(4-ethylphenyl)-1,1‘:3‘,1‘‘-terphenyl-4,4‘‘-diamine) and exhibiting meta connections around a central phenylene ring. In p-EFDP (5‘-phenyl-(N,N,N‘,N‘-tetrakis(4-ethylphenyl)-1,1‘:3‘,1‘‘-terphenyl-4,4‘‘-diamine) there are only two redox sites instead of three. Upon partial oxidation, an intervalence transition is observed from which an electronic coupling very similar to the one of p-EFTP is obtained. In p-FADP (N,N,N‘,N‘,N‘‘,N‘‘-hexakis(4-ethylphenyl)-1,1‘:3‘,1‘‘-terphenyl-4,4‘‘,5‘ triamine) one finds two redox sites of the N,N‘-bis(4-ethylphenyl)-4-aminobiphenyl type, and one redox site of the triphenylamine type. The analysis of the electrochemical behavior and of the intervalence transitions in the mono- and dioxidized species allows the distinction among the different types of electron transfer.