Catalytic Dehalogenation Polymerization of 4,4¢-Dihalogentriphenylamines in the Presence of a Nickel Complex

Abstract Triphenylamine oligomers (OTPAs, n=4-10) weresynthesized by dehalogenation polymerization of 4,4¢-dihalogentriphenylamines. The OTPAs are a white powder,which is stable on exposure to the air and soluble inbenzene, chlorobenzene, chloroform and THF. The OTPAswere characterized by IR, H-NMR and UV-visiblespectroscopy measurements. OTPA films prepared bycasting from solutions or vapor deposition exhibit a highdrift mobility of holes and accordingly double layer organicphotoconductors including the OTPA layer show a highelectrophotographic sensitivity. Introduction While the recent advancement of performance oforganic photoreceptors has made them applicable to high-speed copying machines and printers, the-state-of-artorganic photoreceptors are not necessarily sufficient interms of performance when applied to high- speed copyingmachines and printers. In particular, improvement indurability of organic photoreceptors has been demanded.Although moleculary doped polymer systems, which arewidely used as charge transporting layers (CTLs) exhibitsatisfactory electrical characteristics, they inherently have apoor abrasion resistance because the addition of the chargetransporting molecules to the binder polymer causes adeterioration of a mechanical strength of the binder, andtherefore, the CTL is fragile and has a low tensile strength.It is considered that the above-mentioned deterioration ofthe mechanical strength of the binder polymer causes CTLdisadvantages such as wears, flaws, peelings, and cracks.Further, when applied to electroluminescence devices, alow-weight molecular CTL tends to melt due to generatedJoule’s heat and to crystallize, which cause morphologicchanges of the film. This paper describes the synthesis ofoligomeric triphenylamines, its xerographic properties withexpectation of eliminating the above-mentioneddisadvantages.