a new composition of matter comprising layered compounds of tungsten trioxide and heterocyclic nitrogen or oxygen lewis bases which have a unique layered structure . the layered compounds have the formula lwo 3 where l is a lewis base selected from the group consisting of 5 - membered heterocyclic amines , 6 - membered heterocyclic amines , amine oxides , triorganophosphates , phosphine oxides and sulfoxides , the layered compounds being characterized in that l is covalently bound to a tungsten atom in the tungsten oxide layer .