INTERCALATION OF WEAK LEWIS-BASES INTO HTAWO6.NH2O

The layered Bronsted acid HTaWO6.nH2O forms topochemically the intercalation compounds LxHTaWO6.nH2O with Lewis bases (L) such as heterocycles and aniline derivatives with pK(a) values down to 0.56 for quinoxaline, except acetamide. The fairly rigid molecule, p-aminoazobenzene, is also taken up into the interlayer spaces. Powder X-ray patterns were indexed with the tetragonal cells with alpha-axes which are almost unchanged from the starting material. The basal spacings of some compounds vary with the position of functional groups and the molecular arrangement in the interlayer spaces is deduced from the composition and dependence of basal spacing on the position of functional groups.