Synthesis of Spectral, Thermal and Electrochemical Properties of New Thermally Stable: Blue Light Emitting Materials Based Aromatic Polyamide

A three new triphenylamine-containing aromatic diacid monomers, 4,4'-dicarboxy-4''-phenoxy-triphenylamine (Ma), 4,4'-dicarboxy-4''-(N-pyrrolyl)triphenylamine (Mb), 4,4',4'',4'''-(1,4-phenylenebis(azanetriyl))tetrabenzoic acid (Mc) were successfully synthesized via the aromatic nucleophilic flouro-displacement reaction of 4-fluorobenzonitrile with aniline-derivatives, respectively using sodium hydride as the base, followed by alkaline hydrolysis of the dinitrile intermediate (Ia),(Ib), (Ic).A series of poly(amine-amide)s were prepared by the direct phosphorylation polycondensation from the newly synthesized diacid monomer with various aromatic diamines.FTIR, 1 H and 13 C NMR spectroscopic techniques were used to identify the chemical structures of the intermediate dicyano, carboxylic acid monomer and resultant poly(amine-amide)s.These aromatic poly(amine-amide)s were found to be easily soluble in a variety of organic solvents and could afford strong and hard films via solution casting.They exhibited excellent thermal stability associated with high glass transition temperatures (Tg = 246.28-292.62 °C) and 10 % weight loss temperatures in excess of 578 °C in nitrogen.In dilute NMP solution, these polymers exhibited a medium to strong photoluminescence in the blue region at 423-488 nm.Cyclic voltammetry of the poly(amineamide)s films cast onto an indium tin oxide-coated glass substrate in dry acetonitrile containing 0.1 M of tetrabutylammonium perchlorate (TBAP) as an electrolyte exhibited one oxidation redox couples (Eonset) at (1.32-1.38)V vs Ag/AgCl and revealed electrochromic characteristics with a colour change from pale yellow to blue at applied potentials switched between 0.0 and 1.7 V.