Enthalpy of formation of benzo[k]fluoranthene

Abstract

The standard molar enthalpy of formation of benzo[ k ]fluoranthene, (CAS number 207-08-9) in the crystalline state, at T= 298.15 K, was determined as ΔfHmo(C 20H 12, cr ) = (172.4 ± 4.3)kJ · mol−1, by micro-combustion calorimetry. Vapour pressure against temperature measurements recorded using the Knudsen effusion method led to ΔcrgHmo(C 20H 12) = (124.2 ± 4.7)kJ · mol−1, at T= 298.15 K and hence ΔfHmo(C 20H 12, g ) = (296.6 ± 6.4)kJ · mol−1, at T= 298.15 K. The results reported in this work show that, in terms of the homodesmotic stabilization enthalpy criteria, benzo[ k ]fluoranthene is an aromatic compound, in agreement with the evidence from 1H-NMR spectroscopy, and the prediction by Craig’s rules.