Intercalation compounds of α-zirconium hydrogen phosphate with RhIII ions and RhIII-diamine complexes. Part 1.—Preparation, thermal behaviour and X-ray photoelectron spectroscopy investigation

Abstract

Rhodium(III) can be exchanged between the layers of α-zirconium phosphate by employing the pre-swelled diethanol intercalate, α-Zr(HPO₄)₂(ethanol)₂. During the Rh³⁺/H⁺ exchange, four rhodium-containing phases are formed with different interlayer distances. However, only the fully Rh-exchanged compound, α-ZrRh_0.66(PO₄)₂.4H₂O, is obtained as a pure phase. Rhodium(III) can also be exchanged into the layered intercalation compounds α-Zr(HPO₄)₂(bipy)_0.251.5H₂O (bipy = 2,2′-bipyridyl), α-Zr(HPO₄)₂(phen)_0.52H₂O (phen = 1,10-phenanthroline) and aZr(HPO₄)₂(dmp)_0.5·2.5H₂O (dmp = 2,9-α-dimethyl-1,10-phenanthroline). Exchange is accompanied by a partial elution of the diamine for the phen and dmp derivatives. Various materials are obtained and their thermal properties discussed. X-Ray photoelectron spectroscopy (XPS) gives evidence that Rh^III-diamine complex species mixed N- and O-coordinated Rh^III are formed in the interlayer region of the three intercalation compounds.