Molecular mechanics studies of ketene derivatives and related structures

✍ Scribed by Eugene L. Stewart; J. Phillip Bowen

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 1006 KB
• Volume: 13
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540130913

✦ Synopsis

The MM2 and MM3 force fields have now been parameterized for ketene and its various derivatives. With the addition of the C,,=O bond stretching and C,,2=C,,=O bond bending parameters, calculations were performed on ketene and six substituted ketene compounds. The MM2 results are quite good with only minimal errors in the calculation of C,,z-H bond lengths and H-C,,z-H bond angles. Additionally, C,,2-F bond parameters in MM2 have been re-adjusted to give better results in monofluorinated species, but, unfortunately, resulting in greater error in the polyfluorinated compounds. The results of geometry calculations by MM3 are similar to those obtained by MM2 with the exception of a significant improvement in the geometry of dimethylketene. The MM3 vibrational frequencies calculated in this study are also in good agreement with available experimental and ab initio results with the exception of a few low frequency inand out-of-plane bending modes. @ 1992 by John Wiley & Sons, Inc.