Photochemistry of planar E-hexatrienes: an AM1 study

✍ Scribed by P. Hinrich; J.A. van der Hart; H.J.C. Jacobs

• Book ID: 103993943
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 355 KB
• Volume: 80
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(93)01013-r

✦ Synopsis

The photochemical formation of an allylcyclopropene derivative from E-hexatriene is studied with the AM1 semiempirical method. Two possible reaction mechanisms, with a differing sequence of [1,2]-hydrogen migration aud [1,3]-bond formation, are compared.

In this study a new phenomenon emerged: when three bonds of the triene are twisted by 90', a conical intersection between ground and excited state occurs, through which efficient radiationless decay and product formation can take place. The reaction mechanism in which [1,3]-bond formation is the primary step is the more efficient of the two mechanisms studied, but decay via the conical intersection is somewhat more facile.