A thermochemical study of adducts of 2-pyrrolidone with zinc(III), cadmium(II) and mercury(II) halides

• Published in: Thermochimica acta 1995-06, Vol.256 (2), p.249-260
• Main Authors: Vieira, Eunice F.S., de Queiroz, JoséC., Dias, Francisco S.
• Format: Article
• Language: English
• Subjects: Chemical thermodynamics; Chemistry; Elements, mineral and organic compounds; Enthalpy; Exact sciences and technology; General and physical chemistry; Halide; Pyrrolidone; Thermodynamic properties
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/0040-6031(94)02065-V

The standard molar enthalpies of acid-base reactions in the condensed state ( Δ r H ⦵ ) of the adducts MX 2 · nBuL (where M is Zn, Cd, Hg; X is Cl, Br, I; n = 1, 2, 3; BuL is 2-pyrrolidone) were determined from enthalpies of dissolution ( Δ iH ⦵ ) of metal halide ligands and adducts, at 298.15 K, obtained by calorimetric methods in solution. Using the values of Δ r H ⦵ and auxiliary data from the literature the standard enthalpies of formation ( Δ f H ⦵ ), decomposition ( Δ d H ⦵ ) and lattice enthalpy ( Δ latt H ⦵ ) of these adducts were determined. The enthalpy of vaporization of BuL, Δ vap H ⦵( BuL) , was found to be 41.71 ± 0.56 kJ mol −1 and, from this value, the enthalpies of reaction in the gaseous state ( Δ g H ⦵ ) were estimated. The values of Δ g H ⦵ were used in calculations of the mean dissociation enthalpy of the metal-oxygen bond, D̄(MO), of the obtained adducts, and are correlated with energetic parameters of the metal halides.