Standard molar enthalpies of formation of nickel(II) β-diketonates and monothio-β-diketonates

The standard (p∘ = 0.1 MPa) molar enthalpies of formation of the crystalline diaquobis(dibenzoylmethanate)nickel(II), Ni(dbm)2(H2O)2, diaquobis(thenoyltrifluoroacetonate)nickel(II), Ni(ttfa)2(H2O)2 bis(monothiodibenzoylmethanate)nickel(II), Ni(dbmS)2 and bis(monothiothenoyltrifluoroacetonate)nickel(II), Ni(HttfaS)2 were determined, at T = 298.15 K, by high precision solution-reaction calorimetry. The standard molar enthalpy of sublimation of the monothiothenoyltrifluoroacetone (HttfaS) complex was measured by high-temperature Calvet microcalorimetry. From the standard molar enthalpies of formation of the complexes in the gaseous state, the mean nickel(II)-ligand molar dissociation enthalpies, 〈Dm〉(Ni–L), were derived. ΔfHm∘(cr)/(kJ·mol-1)Diaquobis(dibenzoylmethanate)nickel(II), Ni(dbm)2(H2O)2−993.3 ± 3.8Diaquobis(thenoyltrifluoroacetonate)nickel(II), Ni(ttfa)2(H2O)2−2452.0 ± 8.3Bis(monothiodibenzoylmethanate)nickel(II), Ni(dbmS)2−42.1 ± 5.9Bis(monothiothenoyltrifluoroacetonate)nickel(II), Ni(ttfaS)2−1473.5 ± 8.1Full-size tableTable optionsView in workspaceDownload as CSV