Transformation of 1-Aminonapththalene At The Surface of Smectite Clays

Authors

Calvin C. Ainsworth, Pacific Northwest National Laboratory
Bruce D. Mcveety, Pacific Northwest National Laboratory
Steven C. Smith, Pacific Northwest National LaboratoryFollow
John M. Zachara, Pacific Northwest National LaboratoryFollow

Date of this Version

1991

Citation

Clays and Clay Minerals, Vol. 39, No. 4, 416-427, 1991.

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)-1-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.