Thermochemistry of neutral and protonated 1,7,7-trimethylbicyclo[2.2.1]heptan-2-thione (thiocamphor)

• Published in: Journal of chemical thermodynamics Vol. 31; no. 11; pp. 1457 - 1467
• Main Authors: Roux, M.V., Jiménez, P., Dávalos, J.Z., Notario, R., Abboud, J.-L.M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.1999; Elsevier
• Subjects: 1,7,7-trimethylbicyclo[2.2.1]heptan-2-thione; Chemical thermodynamics; Chemistry; Elements, mineral and organic compounds; enthalpy of combustion; enthalpy of formation; enthalpy of sublimation; Exact sciences and technology; General and physical chemistry; heat capacity; proton affinity; Thermodynamic properties; thiocamphor; enthalpy of combustion; enthalpy of formation; enthalpy of sublimation; heat capacity; proton affinity; 1,7,7-trimethylbicyclo[2.2.1]heptan-2-thione; thiocamphor; Heat of combustion; Knudsen effusion; Vapor pressure; Heat of sublimation; Enthalpy; Experimental study; Combustion bomb; Thione; Bicyclic compound; Calorimetry; Thermal analysis; Thermodynamic properties; Heat of formation
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1006/jcht.1999.0510

The standard molar energy of combustion of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-thione (thiocamphor), [53402-10-1], has been determined by using a rotary-bomb calorimeter. The vapour pressure of the compound was measured between the interval T= 261.96 K to T= 281.66 K, by the Knudsen-effusion technique. From the experimental results of this work, the standard molar enthalpies of combustion, sublimation and formation in the crystalline and gaseous state at the temperature of T= 298.15 K have been derived for thiocamphor: ΔcHmo=−(6736.9 ± 3.3)kJ · mol−1;ΔfHmo(cr)=−(86.8 ± 3.5)kJ · mol−1;ΔsubHmo= (61.7 ± 0.9)kJ · mol−1; and ΔfHmo(g) =−(25.1 ± 3.6)kJ · mol−1. These results have been combined with their gas-phase proton affinities to yield the standard enthalpy of formation of the thiocamphor H+species.