Preparation of Poly(diphenylamine-4,4‘-diyl) and Related Random Copolymers by Organometallic Polycondensation. Electrical, Electrochemical, and Optical Properties

Preparation and properties of poly(arylamine)s prepared by organometallic polycondensation are described. Dehalogenative polycondensation of 4,4‘-dibromodiphenylamine, Br−PhNHPh−Br, with a zerovalent nickel complex affords soluble poly(diphenylamine-4,4‘-diyl), P(DPA) ( n Br−PhNHPh−Br + n Ni (0) Lm → P(DPA)), with M n and M w values of 6.4 × 10 3 and 2.0 × 10 4 and an [η] value of 0.66 dL g -1 in high yield. P(DPA) has a well-regulated structure and been characterized by IR, NMR, and UV−visible spectroscopy, as well as by cyclic voltammetry. The polymer shows a π−π* absorption band and photoluminescence band at 379 and 417 nm, respectively, in NMP. P(DPA) shows two reversible and stable redox cycles at E ° = 0.20 and 0.60 V vs Ag/ Ag + . Dehalogenative copolymerization of Br−PhNHPh−Br with 3,5-dibromotoluene, TolBr 2, with the zerovalent nickel complex gives random copolymers, P(DPA- ran -Tol), and they behave analogously in the electrochemical measurement. Films of P(DPA) and P(DPA- ran -Tol) exhibit electrochromism during their electrochemical oxidation, and the P(DPA) film reversibly changes its color stepwise from light brown to purple through red. P(DPA) shows electrical conductivity of 5 S cm -1 when treated with iodine.