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The standard molar enthalpy of combustion of 2-chlorodibenzo- p -dioxin was redetermined using the sample of high purity by rotating-bomb calorimetry: Δ c H 0 m (cr)=−(5558.2±3.5) kJ · mol −1 . The values of standard molar enthalpies of formation were derived for crystalline and gaseous states: Δ f H 0 m (cr)=−(187.9±3.8) kJ · mol −1 and Δ f H 0 m (g)=−(90.7±3.8) kJ · mol −1 .

The standard molar enthalpy of combustion of fluorinated fullereneC60F48 was determined by rotating-bomb calorimetry,ΔcHmo = − (24638 ± 163)kJ · mol − 1. Using this result and the standard molar enthalpy of sublimation,ΔsubHmo = (109 ± 7)kJ · mol − 1, the values of the standard molar enthalpies of formation of C60F48in the crystalline and gaseous states were found to be − (7563 ± 166)kJ · mol − 1and − (7454 ± 166)kJ · mol − 1, respectively. The enthalpy of reaction C60F48(g) = C60(g) + 48F(g) was calculated,ΔrHmo (298.15 K) = (13800 ± 167)kJ · mol − 1, orΔrHmo (298.15K ) / 48 = (287.5 ± 3.5)kJ · mol − 1.

The standard molar enthalpy of combustion of crystalline 2,3-dichlorodibenzo-p-dioxin was determined by rotating-bomb calorimetry: ΔcHm°=−(5406.4±6.6) kJ·mol−1. Using this result and the standard molar enthalpy of sublimation, ΔsubHm°=(108.6±1.0) kJ·mol−1, the values of the standard molar enthalpies of formation of 2,3-dichlorodibenzo-p-dioxin in the crystalline and gaseous states were found to be −(220.5±6.8) kJ·mol−1and −(111.9±6.9) kJ·mol−1, respectively. The standard molar enthalpy of formation of gaseous 2,3,7,8-tetrachlorodibenzo-p-dioxin was estimated: ΔfHm°(g)≈−164.6 kJ·mol−1.

The standard molar energy of combustion of crystalline 2-chlorodibenzo-p-dioxin was determined by rotating-bomb calorimetry: ΔcUm°= −(5573.6±2.8)kJ·mol−1. The standard molar enthalpy of sublimation was measured in a Calvet microcalorimeter: ΔsubHm°= (97.24±0.55) kJ·mol−1. Using these results, the values of the standard molar enthalpies of formation of 2-chlorodibenxo-p±dioxin in the crystalline and gaseous states were found to be −(171.3 ±3.2)kJ·mol−1and −(74.1±3.3)kJ·mol−1and −(74.1-3.3)kJ·mol−1, respectively.

The energies of combustion of two isomers of trifluorochlorobromoethane have been determined by rotating-bomb calorimetry. The values of the enthalpies of formation: ΔHfo(CF3CHClBr, g) = −(690.4 ± 4.9) kJ mol−1 and ΔHfo(CF2BrCHFCl, g) = −(644.8 ± 6.4) kJ mol−1 were derived. Using the latter value, the enthalpy of formation of trifluorochloroethylene CF2:CFCl was found to be −(500.0 ± 6.5) kJ mol−1.