Chlorine Hyperfine Splittings and Spin Density Distributions of Phenoxy Radicals. An ESR. and Quantum Chemical Study

✍ Scribed by Federico Graf; Klaus Loth; Hans-Heinrich Günthard

• Book ID: 102857854
• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: German
• Weight: 629 KB
• Volume: 60
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19770600304

✦ Synopsis

Abstract

ESR. spectra of the chlorine substituted phenoxy radicals listed in Table 1, which were produced by photo‐oxidation of the parent phenols in aprotic solvents, are reported. In most cases the chlorine splittings could be resolved and analysed in detail. Experimental data as well as quantum chemical calculations were used for assignment of all measured chlorine couplings and determination of their relative signs.

Spin density distributions and polarization parameters for chlorine are discussed and compared with the results from current semiempirical molecular orbital theories.

Chlorine couplings, associated with the larger splittings are found positive in sign, whereas signs of small couplings appear difficult to establish. Limitations in the applicability of McConnell or Karplus‐Fraenkel type relations to chlorine substituted aromatic radicals will be discussed and related to peculiar properties of the spin density matrix of such systems.