Electron Spin Resonance Study of the Cation Radicals of 1,5-Dihydronaphthyridine and Di-N-methyl-1,5-Naphthyridine

Abstract

The e.s.r. spectra of the cation radicals 1,5-di-N-methylnaphthyridine (1) and 1,5-dihydronaphthyridine (2) in trifluoroacetic acid have been reported and analyzed. The splitting constants of 2 are unequivocally assigned by comparison of the spectra of several partially deuterated derivatives. The methyl proton splitting constant of 1 is thought to be low in comparison with other similar radicals and possible reasons for this anomaly are discussed.