An Electron Spin Resonance Study of 1,1′- and 2,2′-Biazulenyl Anion Radicals

The electron spin resonance (ESR) spectra of the anion radicals of 1,1′- and 2,2′-biazulenyls have been examined. The ESR spectrum of the latter shows that the unpaired spin is distributed equally between both azulene rings of the molecule. Theoretical calculation of the spin densities by the McLachlan procedure gave satisfactory agreement with the experimentally estimated densities. The ESR spectrum of the anion radical of 1,1′-biazulenyl, which could only be generated by an electrolytic technique, is explained by the fact that the spin exchange between the two halves of the molecule is slow. However, the ESR spectrum of the anion radical of the 3,3′-dicarbethoxy derivative of 1,1′-isomer showed rapid spin exchange through 1,1′-bond.

[1]  Y. Ikegami,et al.  ESR Spectrum of Tropone Anion Radical , 1968 .

[2]  M. Hirayama,et al.  Electron Spin Resonance of Anion Radicals of Aromatic Esters. IV. The Anion Radicals of Some Substituted Methyl Benzoates , 1968 .

[3]  E. Heilbronner,et al.  Spektroskopische Eigenschaften alkylsubstituierter Diazulyle (Die photochemische Darstellung des 3,3′ und des 2,2′ -Di-guaj-azulyls) , 1968 .

[4]  M. Hirayama.  Electron Spin Resonance of Anion Radicals of Aromatic Esters. III. The Anion Radicals of Several Diesters of Biphenyl- o , o ′- and p , p ′-Dicarboxylic Acids , 1967 .

[5]  N. L. Bauld,et al.  The Cycloheptatrienide Dianion Radical , 1965 .

[6]  A. H. Reddoch.  Systematic Perturbations of the EPR Spectra of Anthracene and Azulene Anions in Solution , 1965 .

[7]  K. Ishizu.  ESR Studies of the Negative Ions of Biphenyl Derivatives. II. Electron Spin Resonance Hyper fine Spectra of 3-Methyl Biphenyl, m,m′-Bitolyl, 2-Methyl Biphenyl, and o,o′-Bitolyl Mononegative Ions , 1964 .

[8]  A. H. Reddoch.  Anomalous Effects in EPR Spectra of the Azulene Anion , 1964 .

[9]  G. Fraenkel,et al.  Analysis of the Electron Spin Resonance Spectra of Aromatic Nitrosubstituted Anion Radicals , 1963 .

[10]  A. Maki,et al.  Intramolecular Electron Transfer in Bis(p‐Nitrophenyl) Anions and Its Effect on Electron Spin Resonance Hyperfine Structure , 1963 .

[11]  G. Fraenkel,et al.  Spin‐Density Distribution in Nitrile Anion Radicals , 1962 .

[12]  I. Bernal,et al.  Electron Spin Resonance of Azulene Anion Radicals , 1962 .

[13]  A. D. McLachlan,et al.  Self-consistent field theory of the electron spin distribution in π-electron radicals , 1960 .

[14]  A. Anderson,et al.  Azulene. VIII. A Study of the Visible Absorption Spectra and Dipole Moments of Some 1- and 1,3-Substituted Azulenes1,2 , 1959 .

[15]  W. Treibs,et al.  Über bi‐ und polycyclische Azulene, XXXIX. Carboxychlorierung von Azulenen , 1959 .

[16]  J. Sarma.  Study of the Motion of Water Molecules in NaBr·2H2O by the NMR Method , 1970 .

[17]  I. Smith,et al.  Electron spin resonance spectrum of the cycloheptatrienyl radical in aqueous solution , 1964 .