Standard enthalpies of formation of 2-thenoyltrifluoroacetone and monothio-2-thenoyltrifluoroacetone by rotating-bomb calorimetry

Standard molar enthalpy of formation of monothiodibenzoylmethane by rotating-bomb calorimetry

“…With the literature values of D f H m (2-butanol, g) ¼ )(292.8 AE 0.7) kJ Á mol À1 [23], D f H m (2-butanethiol, g) ¼ )(96.9 AE 0.9) kJ Á mol À1 [23], D f H m (C 6 H 5 OH, g) ¼ )(96.4 AE 0.9) kJ Á mol À1 [23] and D f H m (C 6 H 5 SH, g) ¼ (111.3 AE 1.3) kJ Á mol À1 [23], the following increments in the standard molar enthalpies of formation are calculated: These results confirm, as previously reported [1], that the enthalpic increment in the monothio-b-diketones is ca. 20 kJ Á mol À1 larger than in the thiophenol and so, that the intramolecular hydrogen bond energy in (O-HÁ Á ÁO) is stronger than in the (S-HÁ Á ÁO).…”

“…In a previous paper [1] we reported the determination of the standard molar enthalpies of formation of thenoyltrifluoracetylacetone and its monothio derivative.…”

“…For each compound, the products of combustion in the experiments consist of gaseous phase and an aqueous mixture of sulphuric acid for which the thermodynamic properties are known. The values of Du o c refer to the reaction described by equation (1). Table 2 lists the individual values of D c u together with the mean and its standard deviation.…”

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

“…The authors have published the results in a form of the difference between the enthalpy of formation of the ligand and of the complex since the standard molar enthalpy of formation of the ligand (monothiodipivaloylmethane) was unavailable. Based on the previous work [20,40] the standard molar enthalpy of formation of the monothiodipivaloylmethane in the gas phase can be estimated as D f H m ðHdpmSÞ ¼ Àð299 AE 11Þ kJ Á mol À1 and, using the reported data [18], the standard molar enthalpy of formation of the bis(monothiodipivaloylmethanate)nickel(II), in the gas and solid phases, can be derived as D f H m ½NiðdpmSÞ 2 ; g ¼ Àð688 AE 24Þ kJ Á mol À1 , and as D f H m ½NiðdpmSÞ 2 ; cr ¼ Àð805 AE 24ÞkJ Á mol À1 . The standard molar enthalpies of formation of the crystalline bis(monothiodibenzoylmethanate)nickel(II), Ni(DBMS) 2 , was determined, independently, in the University of Porto and in the University of Wrocław, using two different reactions, yielding results that are in excellent agreement and so we consider the average of the two experimental determinations.…”