The synchronous-transit method for determining reaction pathways and locating molecular transition states

✍ Scribed by Thomas A. Halgren; William N. Lipscomb

• Publisher: Elsevier Science
• Year: 1977
• Tongue: English
• Weight: 818 KB
• Volume: 49
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(77)80574-5

✦ Synopsis

In the synchronous-transit method, a model Iinear s_vtzcizmtzous transit pathway is tirst constructed and is than relined by optimizing one or more intermediate structures subject to the constraint that the optimized structure retain the same relative position along the path (orthogonal optitnixtiotz).

The method yields a series of energy estimates which progressive!y bound the energy of the transition state from above and from below. High computational efficiency is attainable, and sufticient flesibility is provided to deal with asynchronous processes. Comparisons are made to the alternative "reacrion-coordinate" approach, which is shown to be subject to several serious deficiencies. The method is applied to a model two-dimensional energy surface and to the allowad electrocyclic interconversions of the cyctopropyl and ally1 cations and of cyclobutene and cis-butadienc.