The intercalation of acetone and butan-2-one in vanadyl and niobyl phosphat
es and niobyl arsenate is reported. All intercalates prepared are tetragona
l and their basal spacings are close to each other. The intercalates contai
n one molecule of the ketone per formula unit. The existence of keto-enol t
automerism of guest molecules in interlayer space is assumed.