PHOTOCHEMICAL BEHAVIOR OF METAL-COMPLEXES INTERCALATED IN ZIRCONIUM-PHOSPHATE

Intercalation compounds of α-Zr(HPO4)2 · H2O (α-ZrP) with Cr(NH3)+36, Cr(en)+33 (en = ethylenediamine), Co(NH3)+36, Co(en)+33, and Fe(C5H5)+2 have been prepared by aqueous ion exchange with the n-butylamine derivative of α-ZrP, (C4H9NH3)2Zr(PO4)2. X-ray powder diffraction was used to determine interlayer spacings. Irradiation of intercalated Cr(en)+33 with a Hg-vapor lamp (λmax = 254nm) resulted in a red shift of the ligand field absorption maximum from 457 to 560 nm, suggesting loss of all coordinated ethylenediamine and substitution by lattice water and phosphate. Irradiation of Cr(NH3)+36 results in a smaller red shift, suggesting kinetic stabilization of the ammine complex by inclusion in the phosphate host. The iron and cobalt complexes do not react under similar photolysis conditions, in contrast to their behavior in aqueous solution, where reduced complexes result. The potential for use of host lattices in stabilization of unstable species is discussed. © 1991 Academic Press, Inc.