The Standard Enthalpy of Formation of the 1-Adamantyl Cation in the Gas Phase. An Experimental and ab Initio Re-assessment

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 103; no. 38; pp. 7555 - 7557
• Main Authors: Flores, H, Dávalos, Abboud, J.-L. M, Castaño, O, Gomperts, R, Jiménez, P, Notario, R, Roux, M. V
• Format: Journal Article
• Language: English
• Published: American Chemical Society 23.09.1999
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp991262u

The standard molar enthalpy of formation of gaseous 1-adamantyl chloride (1Cl,g) was determined experimentally by means of thermochemical techniques. Ab initio quantum-chemical calculations at the G2(MP2) level were performed on adamantyl cation (1 +) and on 1Cl. Combination of these data with other experimental and computational results for adamantane (1H), isobutane (2H), tert-butyl cation (2 +), and tert-butyl chloride (2Cl) provided purely experimental and purely computational, independent values for the standard enthalpy and Gibbs energy changes for reactions 1 and 2: where X = Cl. This information was used to determine a value of 162.0 ± 2.0 kcal mol-1 for the standard molar enthalpy of formation of gaseous 1 +, Δf H°m(1 +,g).