251. Synthesis, luminescence and electrochromism of aromatic poly(amine–amide)s with pendent triphenylamine moieties
- Author
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Guey-Sheng Liou, Tzy-Hsiang Su, and Sheng-Huei Hsiao
- Subjects
chemistry.chemical_classification ,General Chemistry ,Triphenylamine ,Photochemistry ,chemistry.chemical_compound ,Monomer ,Dicarboxylic acid ,chemistry ,Electrochromism ,Amide ,Diamine ,Polymer chemistry ,Materials Chemistry ,Amine gas treating ,Amination - Abstract
A new triphenylamine-containing aromatic dicarboxylic acid monomer, N,N-bis(4-carboxyphenyl)-N′,N′-diphenyl-1,4-phenylenediamine (2), was synthesized from the amination reaction between 4-aminotriphenylamine and 4-fluorobenzonitrile and subsequent alkaline hydrolysis of the dinitrile intermediate. A series of novel aromatic poly(amine–amide)s with triphenylamine units in the main chain and as the pendent group were prepared from the newly synthesized dicarboxylic acid and various aromatic diamines. These poly(amine–amide)s were amorphous and readily soluble in many organic solvents. All the polymers could be solution-cast into flexible films with good mechanical properties. They had excellent levels of thermal stability associated with high glass-transition temperatures (226–261 °C). These polymers exhibited strong UV–vis absorption bands at 350–365 nm in NMP solution. Their photoluminescence spectra showed maximum bands around 512–543 nm in the green region. The hole-transporting and electrochromic properties are examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine–amide) 5a prepared from the dicarboxylic acid monomer 2 with a structurally similar diamine monomer N,N-bis(4-aminophenyl)-N′,N′-diphenyl-1,4-phenylenediamine (4a) exhibited four reversible oxidation redox couples in acetonitrile solution at E1/2 = 0.60, 0.80, 0.97 and 1.13 V, respectively. All the poly(amine–amide)s exhibited excellent reversibility of electrochromic characteristics by continuous five cyclic scans between 0.0 to 1.30 V, with a color change from the original pale yellowish neutral form to the green and then to blue oxidized forms.
- Published
- 2005