Standard molar enthalpies of formation of 2-chloroquinoline, 4-chloroquinoline, 6-chloroquinoline and 4,7-dichloroquinoline by rotating-bomb calorimetry

The standard (p∘ = 0.1 MPa) molar enthalpies of combustion, ΔcHm∘, for crystalline 2-, 4-, 6-chloroquinoline and 4,7-dichloroquinoline were determined at the temperature 298.15 K using a rotating-bomb combustion calorimeter. The standard molar enthalpies of sublimation, ΔcrgHm∘, at T =  298.15 K, were determined by Calvet microcalorimetry. The results were as follows:-ΔcHm∘(cr)/(kJ·mol-1)ΔcrgHm∘/(kJ·mol-1)2-Chloroquinoline4492.5 ± 1.684.3 ± 2.64-Chloroquinoline4508.4 ± 1.678.6 ± 1.76-Chloroquinoline4508.2 ± 1.680.8 ± 1.94,7-Dichloroquinoline4353.3 ± 1.389.5 ± 2.3Full-size tableTable optionsView in workspaceDownload as CSVThese values were used to derive the standard molar enthalpies of formation of the compounds in their crystalline and gaseous phases, respectively. The derived standard molar enthalpies of formation, in the gaseous state, are analysed in terms of enthalpic increments and interpreted in terms of molecular structure.