Molten LiNO 2-NaNO 2, LiNO 2-KNO 2, LiNO 2-CsNO 2, and NaNO 2-KNO 2 Eutectics: the reaction of PdCl 2, K 2PdCl 4, K 2Pd(NO 2) 4, PtCl 2, K 2PtCl 4, K 2Pt(NO 2) 4, PtCl 4, and K 2PtCl 6

Abstract

The reaction of eight compounds of Pd(II), Pt(II) and Pt(IV) with four molten nitrite eutectics were studied and their stoichiometries were deduced using thermogravimetric analysis. Their behaviour revealed an interesting class of oxidation-reduction reactions in which the nitrite melt acted as the reducting agent. Infrared spectra and high-temperature absorption spectra were used to identify the complex species formed in these melts. At low temperatures, Pd(II) and Pt(II) dissolved in the nitrite melts forming clear yellow solutions of nitro/nitrito species of Pd(II) and Pt(II), respectively. These solutions decomposed at higher temperatures, evolving nitrogen dioxide and leaving black residues of Pd and Pt metals. Pt(IV) formed an insoluble nitro/nitrito species that reacted in two stages, first to Pt(II) and eventually to Pt metal.