Antimony pentachloride affinity

Among numerous thermodynamic measurements on the complexes of covalent metal halides, antimony pentachloride was chosen by Gutmann (1966-1968) [78] as the reference Lewis acid for constructing an SbCls affinity scale and developing the donor number concept. This scale is critically presented in Chapter 2. 

Gutmann [Gu 67] made systematic examinations with a large number of solvents, which were characterized by their affinities towards antimony(V) pentachloride as the reference acceptor. Gutmann s proposed donicity value is the heat of solvation of antimony(V) chloride by various solvents (in dilute solutions prepared in an inert solvent), determined calorimetrically and expressed in kcal/mole. 

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