Pyramidal geometry of the tervalent carbon atom of the norbornadien-7-yl radical; electron spin resonance study

Abstract

The e.s.r. spectrum of the norbornadien-7-yl radical shows that its trigonal carbon atom (C_α) is more pyramidal than that of the cyclopropyl radical; it is suggested that the pyramidal deformation of the former is due to electron transfer interaction from the etheno bridges to C_α as well as to the small bond angle around C_α.