Coordination Compounds in Melts

Abstract

The first information about the possibility of existence of complex compounds in molten salts was based on investigations using thermal phase analysis. The presence of well-defined maxima (distectic points) in liquidus curves in phase diagrams for binary salt systems indicates the formation of such compounds, which separate out as a solid phase. In the opinion of many authors, they must be also in the liquid (molten) phase, at least at temperatures close to liquidus. This hypothesis, however, was called in question by some authors, who stated that the presence of distectic points in phase diagrams does not suggest that there are complex compounds of definite composition in salt melts. Therefore, as early as 30–40 years ago, the possibility of existence of such complex compounds in salt melts was a point at issue.