Thermochemistry of cobalt(II)chloride pyridine complexes

Abstract

The depyridination of cobalt(II) chloride-6-pyridine (CoCl₂,6py) was investigated. The results can be summarized as CoCl₂,(n)py_(solid)= CoCl₂,(m)py_(solid)+(n – m)py_(vapour) where n is 6,4, 2(β-form), 1 and ⅔m is 4, 2(α-form), ⅔, and 0. The enthalpy and entropy were calculated from the behaviour of the vapour pressure as a function of temperature. Magnetic moments were determined. The probable structure of the unknown pyridine solvates are discussed on the basis of the chemical and physical evidence and the structures that are known.