An Electron Spin Resonance Study of the Reaction of Pyridine with Potassium: The Formation of Bipyridyl Negative Ion1

An electron spin resonance study of the product of the reaction of potassium metal with pyridine in 1,2-dimethoxyethane was performed. Deuterated species were synthesized and their negative ions prepared. A comparison of these paramagnetic species with the negative ion of 4,4'bipyridyl indicates that pyridine undergoes a coupling reaction. Hyperfine coupling constants were determined for all the magnetic nuclei, and the concept of spin density on the nitrogen atom is discussed. (auth)