Cyclopropyl substituents, delocalized through

The solvolysis product distribution and the kinetic data (solvent effect33) m = 0.583 — 0.505, substituent effect34) q = —2.98) were clearly consistent with a SNj ionization process involving the anchimeric assistance of the triple bond (kA) 35) leading to the resonance stabilized cation 63 with its positive charge delocalized through the adjacent triple bond into the aryl (or cyclopropyl) group 13). 

E. Systems having Remote Cyclopropyl Substituents which are delocalized through... 

The available evidence points to the conclusion that a-chloro, a-bromo and a-iodo substituents on a cyclopropyl radical do not help to maintain its configuration. The radical is either a rapidly inverting <7-radical or a 7r-radical due to delocalization of the radical through the use of available d orbitals of the halogens (Cl, Br, I). 

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