title: Influence of connector groups on the interactions of substituents with carbon-centered radicals.
abstract: High-level G3X(MP2)-RAD calculations have been carried out to examine the effect of interposing a "connector" group (W) on the interaction between a substituent (X) and the radical center in carbon-centered radicals ((•)CH(2)-W-X). The connector groups include -CH(2)-, -CH═CH-, -C≡C-, -p-C(6)H(4)-, -m-C(6)H(4)-, and -o-C(6)H(4)-, and the substituents include H, CF(3), CH(3), CH═O, NH(2), and CH═CH(2). Analysis of the results is facilitated by introducing two new quantities termed radical connector energies and molecule connector energies. We find that the -CH(2)- connector effectively turns off π-electron effects but allows the transmission of σ-electron effects, albeit at a reduced level. The effect of a substituent X attached to the -CH═CH- and -C≡C- connector groups is to represent a perturbation of the effect of the connector groups themselves (i.e., CH═CH(2) and C≡CH).
authors.affiliation: School of Chemistry and ARC Center of Excellence for Free Radical Chemistry and Biotechnology, University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Ambili S
authors.initials: AS
authors.lastname: Menon
authors.forename: Thomas
authors.initials: T
authors.lastname: Bally
authors.forename: Leo
authors.initials: L
authors.lastname: Radom
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D009930:Organic Chemicals / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: D005609:Free Radicals; D009930:Organic Chemicals; D002244:Carbon