N-ALKYLATION AND N-ACYLATION OF POLYANILINE AND ITS EFFECT ON SOLUBILITY AND ELECTRICAL-CONDUCTIVITY

Various alkylating and acylating agents, with different electrophilici ty, were allowed to react with polyaniline ''emeraldine base'' (Pan-EB ) or its anion. Replacing the N-hydrogens of polyaniline by Various ac yl or benzyl groups strongly affected the solubility and the electrica l conductivity of the polymer. Neutral Pan-EB was reacted with benzoyl chloride, p-t-butylbenzoyl chloride or pivaloyl chloride in N,N'-dime thylpropylene urea (DMPU) solutions. While the benzoyl and pivaloyl de rivatives showed very poor solubility in common organic solvents, the p-t-butylbenzoyl derivative was readily soluble in THF, chloroform, DM SO, etc. As expected, these acyl derivatives showed diminished electri cal conductivity relative to that of the parent Pan-EB. Benzyl chlorid es did not react with neutral Pan-EB. Attempts to prepare solutions of the nitrogen anion of Pan-EB by reaction with sodium hydride in DMSO or DMPU led invariably to crosslinked insoluble material. This was asc ribed to Michael addition of the formed nitrogen anions to the quinoni mine moieties. However forming the nitrogen anion in presence of p-t-b utylbenzyl chloride trapped it to form N-benzylated Pan-EB. This was a soluble high molecular weight, electrically conductive (4.3 x 10(-1) S cm(-1) as the hydrochloride) N-alkyl Pan-EB. Reacting Pan-EB with ex cess of both sodium hydride and benzyl chlorides led to film-forming p er-benzylated Pan-leucoemeraldine reduced form. (C) 1997 John Wiley & Sons, Inc.