Topological investigations of the state of some transition-metal ions in some binary mixtures of non-electrolytes: molar excess volumes

Abstract

Molar excess volumes have been measured at 308.15 K for binary mixtures of pyridine (A) saturated with anhydrous CoCl₂(S), denoted A(S), with aniline, o-toluidine, formamide or N,N-dimethylformamide, denoted (B), and the results have been rationalized to suggest that the saturation of pyridine with anhydrous CoCl₂ converts the octahedrally coordinated Co²⁺(in anhydrous CoCl₂) into tetrahedrally coordinated Co²⁺ in such neutral entities as Cl₂Co(Py)₂; and that the addition of B to A(S) results in the formation of molecular entities of the type Cl₂Co(Py)B. These conclusions have been supported by infrared- and molar mass-spectroscopic studies.