Standard molar enthalpies of formation of two crystalline bis[ N-(diethylaminothiocarbonyl)benzamidinato]nickel(II) complexes

Abstract

The standard ( p ∘=0.1 MPa) molar enthalpies of formation of the crystalline complexes bis[ N-( N″, N″-diethylaminothiocarbonyl)benzamidinato]nickel(II), {Ni(datb) 2}, and bis[ N-( N″, N″-diethylaminothiocarbonyl)- N ′-phenylbenzamidinato]nickel(II), {Ni(datpb) 2}, were determined, at T=298.15 K, by high precision solution-reaction calorimetry. Δ f H m ∘ (cr)/(kJ · mol −1) Ni(datb) 2 6.5 ± 7.9 Ni(datpb) 2 285.1 ± 11.3 From the obtained results, the metal–ligand exchange enthalpies in the crystalline phase were derived. The enthalpy of a hypothetical metal–ligand exchange reaction in the crystalline phase was derived, thus allowing a discussion of the energetics of complexation in comparison with known crystal-structural parameters.