Pergamon Po/ykedronVol. 13, No. 8,pp. 1311-1314, 1994 Copyright 0 1994 Elsevier Science Ltd Printed in Great Britain. All rinhts reserved 0277-5387/94 -.$7.00+0.00 POLYMERIZATION OF ANILINE ON COPPER ZIRCONIUM PHOSPHATE AND A MIXED ZIRCONIUM PHOSPHONATE GUY L. ROSENTHAL,* JAMES CARUSO and SIMON G. STONE Department of Chemistry, University of Vermont, Burlington, VT 05405, U.S.A. Abstract-Oxidative polymerization of aniline was performed using both CuZr(P04)2 (CuZrP) and Zr[03P(CH2)3COOH]o,75(03POH),,~~ [ZrP(bt)o,7,(OH),,~,] as catalysts. In the CuZrP reactiorl, the non-conducting emeraldine base form of polyaniline (PANI) formed on the surfaces of the phosphate microcrystals. When exposed to HCl, the solid CuZrP * PAN1 turned from violet to green, indicating formation of a protonated conducting polymer. In the reaction with the mixed phosphonate ZrP(bt)o.7s(OH),.25, a violet product also formed, with the interlayer spacing of the solid increasing significantly, indicating polymerization within the interlamellar region. The solid product did not react with HCl. IR spectra indicated a slightly different form of PAN1 included in the phosphonate than on the surface of CuZrP. Polyaniline (PANI) has generated a significant amount of interest in the past 10-20 years, not only for its electronic properties, but also for the variety of different forms of the polymer that can form under different reaction conditions and upon chemical and electrochemical treatments.’ Thus, it offers the lure to the materials chemist of a polymer whose physical properties can potentially be tail- ored by chemical means to fit various applications. We are involved in constructing microporous materials for applications as catalysts, molecular sieves and as templates for synthesis of nano- structures with novel electronic properties. By using microporous catalysts in PAN1 synthesis, it may be possible to construct polymeric chains, insulated from each other by the dielectric porous host, which display quantum-size effects on their electronic and optical properties.’ or-Zirconium phosphates and phosphonates are families of layered solids based upon the cr-zir- conium phosphate, Zr(03POH), - H,O (a-ZrP), structure, in which layers of zirconium atoms are linked via PO3 pyramids. In a-ZrP itself, the protons are exchangeable with a variety of cations which *Author to whom correspondence should be addressed. then occupy the galleries between layers.3 In pho- sphonates, Zr(O,PR), * H20, the potential for ion exchange is not necessarily present ; however, func- tional groups on the organic moiety can offer sites for significant chemical reactivity: provided the interlayer gallery is porous enough to allow exposure of these interlamellar sites to the sur- rounding medium. The possibility exists for rational construction of porous mixed phosphonates, Zr(O,PR), (03PR’L, in which two organic groups of different size and shape can be oriented randomly in the interlayer galleries (Fig. l).’ In these materials, the dimensions of pores are determined by the composition of the solid solution and by the size mismatch between the organic moieties.6 The potential of these porous mixed phosphonates as zeolitic catalysts is only beginning to be explored. In this study, we have compared the catalytic behaviour of Zr(03P(CH2)3COOH)0.75(03PCH3)1.25, a relatively non-porous mixed phosphonate, in the aniline polymerization reaction with that of copper zirconium phosphate, CuZr(P04)z * Hz0 (CuZrP). In CuZrP, intercalated Cu2+ ions, effective catalysts for this reaction in aqueous solution, are exposed to aniline at the surfaces of phosphate microcrystals only. 1311