Novel aromatic polyamides and polyimides functionalized with 4-tert-butyltriphenylamine groups

A new triphenylamine-containing diamine monomer, 4,4'-diamino-4"-tertbutyltriphenylamine, was successfully synthesized by the cesium fluoride-mediated N,N-diarylation of 4-tert-butylaniline with 4-fluoronitrobenzene, followed by the reduction of the nitro group. The obtained diamine monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce two series of novel triphenylamine-based polyamides and polyimides with pendent tert-butyl substituents. Most of the polymers were readily soluble in polar organic solvents, such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide (DMAc), and could be solution cast into tough and flexible polymer films. These polymers showed high glass transition temperatures between 282 and 320 degrees C, and they were fairly stable up to a temperature above 450 degrees C (for polyamides) or 500 degrees C (for polyimides). These polymers exhibited UV absorption maxima around 308 to 361 nm. The photoluminescence spectra of the polyamides in DMAc exhibited a peak emission wavelength in the blue at 421-433 nm. Cyclic voltammograms of polyamides and polyimides showed an oxidation wave at 1.0-1.1 V versus Ag/AgCl in an acetonitrile solution. All the polyamides and polyimides exhibited excellent reversibility of electrochromic characteristics by continuous several cyclic scans between 0.0 and 1.1-1.3 V, with a color change from the original pale yellowish neutral form to the green or blue oxidized forms. (c) 2006 Wiley Periodicals, Inc.