Transformation of 1-Aminonapththalene at the Surface of Smectite Clays

Calvin C. Ainsworth, Bruce D. McVeety, Steven C. Smith and John M. Zachara
Pacific Northwest Laboratory P.O. Box 999, MSN K3-61, Richland, Washington 99352

Abstract: One-aminonaphthalene is sorbed onto the Na-saturated smectite clays, montmorillonite and hectorite, by cation exchange. In the presence of Fe3+, either in the clay structure or on the clay surface, sorption is followed by the formation of a blue-colored complex, with the continuous disappearance of aminonaphthalene from solution and the clay surface. The rate of aminonaphthalene disappearance decreases as pH increases. With time, four major products that appear to be structural isomers of N(4-aminonaphthyl)-l-naphthylamine are produced. A simplified model of this transformation is suggested to be the oxidation by Fe3+ of sorbed aminonaphthalene forming a radical cation-clay complex. A subsequent reaction between the radical-cation and a neutral aminonaphthalene molecule takes place, with the products being strongly sorbed to the clay surface.

Key Words: Polymerization • Smectite • Sorption • Surface catalysis

Clays and Clay Minerals; August 1991 v. 39; no. 4; p. 416-427; DOI: 10.1346/CCMN.1991.0390411
© 1991, The Clay Minerals Society
Clay Minerals Society (www.clays.org)