Abstract
Recent CASPT2 calculations of the heats of formation of the isomeric benzynes by R. Lindh and M. Schütz [Chem. Phys. Lett. 258 (1996) 409] are re-examined. The unrealistically low value reported for p-benzyne (132.7 kcal/mol) is shown to be an artifact of the use of incorrect CASSCF and CASPT2 energies for p-benzyne, as well as a flawed isodesmic reaction analysis. Use of the correct energies and an appropriate isodesmic reaction leads to excellent agreement between the calculated and measured heats of formation for p-benzyne. The performance of coupled-cluster methods and density functional theory in predicting benzyne thermochemistry and singlet-triplet splittings is also evaluated.
Original language | English (US) |
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Pages (from-to) | 311-320 |
Number of pages | 10 |
Journal | Chemical Physics Letters |
Volume | 277 |
Issue number | 4 |
DOIs | |
State | Published - Oct 10 1997 |
Bibliographical note
Funding Information:This work was supported by the National Science Foundation (CJC and RRS) and the Alfred P. Sloan Foundation (CJC).