T. S. Papina

The standard enthalpy of formation of fullerene chloride C60Cl30

A rotating-bomb calorimeter was used to measure the energy of combustion of crystalline fullerene chloride C60Cl30 · 0.09Cl2, ΔcU° = (−24474 ± 135 kJ/mol). The result was used to calculate the standard enthalpy of formation, ΔfH° (C60Cl30, cr) = 135 ± 135 kJ/mol, and the C-Cl bond energy, 195 ± 5 kJ/mol. The C-X (X = F, F, Cl, and Br) bond energies in fullerene C60 derivatives and other organic compounds are compared.

The standard enthalpy of formation of 1,2,3,4-tetrachlorodibenzo-p-dioxine

The energy of combustion of crystalline 1,2,3,4-tetrachlorodibenzo-p-dioxine (-5122.9 ± 7.4 kJ/mol) was measured using an isothermic-shell calorimeter with a rotating platinum plated bomb. The result was used to calculate the enthalpy of combustion (-5120.4 ± 7.4 kJ/mol) and formation (−267.8 ± 7.6 kJ/mol) for the crystalline state. The enthalpy of sublimation was measured using a Calvet microcalorimeter at 411.5 K (116.0 ± 2.6 kJ/mol); recalculation to T = 298.15 K gave 118.7 ± 2.6 kJ/mol. The enthalpy of formation of 1,2,3,4-tetrachlorodibenzo-p-dioxine in the gas state was calculated (−149.1 ± 8.0 kJ/mol)

The enthalpy of formation of fullerene fluoride C60F18 and the C-F bond energy

The enthalpy of combustion of crystalline fullerene fluoride C60F18 was determined in an isoperibolic calorimeter with a rotating platinized bomb, and the enthalpy of formation of the compound was calculated. The enthalpy of sublimation of C60F18 measured earlier was used to calculate the enthalpy of formation of fullerene fluoride in the gas phase and the mean enthalpy of dissociation of C-F bonds in this compound.

Standard formation enthalpies for α-amino acids: L-serine, L-arginine, and L-tyrosine

The energies of combustion, ΔcU0, of three amino acids: L-serine (I), L-arginine (II) and L-tyrosine (III) in the crystalline state at 298.15 K were determined using a static-bomb isoperibolic calorimeter. From these data, the enthalpies of combustion, ΔcH0, and the enthalpies of formation, ΔfH0, are calculated. The ΔfH0 values are compared with the published data.

Standard enthalpy of β-alanine formation

In an isoperibolic calorimeter with a stationary bomb, the value of the combustion energy of crystalline β-alanine (ΔcU0) was determined at 298.15 K, from which standard enthalpies of combustion (ΔcU0) and formation (ΔcU0) have been calculated. The obtained results are compared with literature data.

Standard enthalpy of formation of fullerene bromide C60Br24

The enthalpy of the combustion of C60Br24 · 2Br2 has been measured using a rotating-bomb calorimeter as follows: ΔcH0(C60Br24 · 2Br2, cr) = (−25986 ± 166) kJ/mol. The result has been used to calculate the standard enthalpy of formation, ΔfH0(C60Br24 · 2Br2, cr) = (2375 ± 166) kJ/mol. The enthalpies of formation of C60Br24 (cr) and dissociation of the C-Br bond have been estimated. The latter value has been compared with enthalpies for the C-X (X = H, F, Cl, Br) bonds in fullerene derivatives and organic compounds.

Enthalpy of formation of perfluoro-2,7-dimethyloctane

Abstract The energy of combustion of perfluoro-2,7-dimethyloctane has been measured in a rotating bomb calorimeter, Δ c U 0 (1) = −3198.2 ± 8.6 kJ mol −1 . The enthalpy of formation, Δ f H 0 (1) has been obtained by combination of the experimental data with the accepted values for the enthalpies of formation of water, carbon dioxide and aqueous hydrofluoric acid.

The enthalpies of formation of 1,1,1-trifluoro-2-chloro-2-bromoethane and 1,1,2-trifluoro-2-chloro-1-bromoethane

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.

Standard Enthalpies of Formation of Perfluoro(2-methyl-3-oxa)hexanoic and Perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic Acids

The energies of combustion of perfluoro(2-methyl-3-oxa)hexanoic and perfluoro(2,5-dimethyl-3,6-dioxa)nonanoic acids are for the first time measured in a calorimeter with a rotating platinized bomb and used to calculate the standard enthalpies of formation of these compounds in the liquid state. Based on the enthalpies of formation, the contribution from the [-CF2OCF(CF3)-] group to the enthalpies of formation of perfluoro acids is calculated.

Standard enthalpy of formation of fluorinated graphite CF0.96

The energy of combustion ΔcU0 of fluorinated graphite CF0.96 has been determined using an isoperibolic calorimeter with a rotating platinized bomb and the enthalpy of formation ΔfH0 thereof has been calculated. The enthalpy of the dissociation of the C-F bond has been calculated from the obtained value of ΔfH0(CF0.96) and compared with analogous values for the previously investigated C60 fullerene fluorides.