Synthesis and electrochromism of novel organosoluble polyarylates bearing triphenylarnine moieties

[[abstract]]A series of novel aromatic polyarylates with triphenylamine units in the main chain and as the pendent group were prepared from the dicarboxylic acid monomer, N,N-bis(4-carboxyphenyl)-N', N'-diphenyl-1,4-phenylenediamine (1), and various bisphenols. These polyarylates were amorphous and readily soluble in common organic solvents. They had excellent levels of thermal stability associated with moderately high T-g values (182-263 degrees C). These polymers exhibited strong UV-vis absorption bands at 357-360 nm in toluene solution and the photoluminescence spectra showed maximum bands around 493-503 nm in the green region. The hole-transporting and electrochromic properties were examined by electrochemical and spectro-electrochemical methods. Cyclic voltammograms of the polyarylates exhibited two reversible oxidation redox couples in acetonitrile solution at E-onset 0.77-0.79 V and 1.12-1.14 V, respectively. The typical polymer 3b film revealed good stability of electrochromic characteristics, with color change from colorless to green and blue at applied potentials ranging from 0.00 to 1.24 V These anodically polymeric electrochromic materials not only showed excellent reversible electrochromic stability with good green coloration efficiency (CE = 159 cm (2)/C) and blue coloration efficiency 2/C (CE = 154 cm(2)/C) but also exhibited high contrast of optical transmittance change (Delta T%), 54% in 895 nm for green color and up to 84% in 595 nm for blue color. After over 100 cyclic switches, the polymer films still exhibited excellent stability of electrochromic characteristics. V 2007 Wiley Periodicals, Inc.[[note]]SC