Ion exchange of ruthenium cationic complexes by α-tin(IV) bismonohydrogenphosphate

Abstract

The ion exchange from aqueous solution of some cationic ruthenium species by α-tin(IV) bismonohydrogenphosphate (SnP) has been investigated. There is a marked difference in behaviour according to the cationic species which are used. Thus the stable [Ru(NH₃)₆]³⁺ is only exchanged on the surface, ruthenium red [Ru₃O₂(NH₃)₁₄]⁶⁺ and ruthenium nitrosyl species were ion exchanged onto the surface from dilute solutions but, at higher concentrations, the host SnP, and its butylamine intercalation compound SnP–BuA, were delaminated to give disordered non-crystalline materials In contrast, the reactive [Ru(NH₃)₆]²⁺ was rapidly extracted in an autocatalytic, topotactic reaction to give a polyphasic but microcrystalline intercalation compound, the layered structure of which was retained on heating At high loadings there appears to be an interlamellar electron transfer resulting in the oxidation of ruthenium(II) to ruthenium(III) probably with tran-[Ru(H₂O)₂(NH₃)₄]³⁺ as the dominant guest cation.