Mat. Res. Bull., Vol. 17, pp. 443-449, 1982. Printed in the USA. 0025-5408/82/040443-07503.00/0 CopyHght (e) 1982 Pergamon Press Ltd. A MILD TRANSFORMATION OF T-FeOOH TO y-Fe20 3 USING ORGANIC REAGENTS Gautam R. Desiraju and Madan Rao School of Chemistry University of Hyderabad Hyderabad-500134(INDIA) (Reeeived January 18, 1982; Communicated by C.N.R. Rao) ABSTRACT The layered compound, FeOCI is known to form stable intercalates with a large number of organic molecules. When the isostructural y-FeOOH i~ treated with organic bases at temperatures of 120-140 C, it is quantitatively converted to the topotactically related y-Fe203. The first step in this base assisted dehydration is presu_ med to be an intercalation. The second and possibly faster step could be a sequential elimination of water from the interlayer, the role of the base being cataly_ tic. Slightly impure samples of y-FeOOH that contain a small (~) amount of a-FeOOH are transformed quanti- tatively into ~-Fe203 under the above conditions but pure ~-FeOOH is unaffected. A possible rationale for this observation is given. Introduction Intercalation compounds of the layered compound FeOCl have been extensively studied and a large number of small organic molecules, especially heterocyclic bases, from isolable interca- lates of fixed stoichiometry (1,2,3). However, the isostructural y-FeOOH has not been investigated similarly. In both the FeOCI and y-FeOOH structures the layers consist of corrugated sheets of edge and corner shared cis-FeO4X 2 octahedra (X=CI for FeOCI and X=OH for y-FeOOH) with the X groups on the outer sides of the layers. (Figures 1 and 2) 443