Calculation of enthalpies of hydrogenation of hydrocarbons

✍ Scribed by Mustafa R. Ibrahim; Zacharia A. Fataftah; Paul von Ragué Schleyer; Peter D. Stout

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 679 KB
• Volume: 8
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540080810

✦ Synopsis

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogenand oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.