Physical Properties and Chemical Reactivity of Alternant Hydrocarbons and Related Compounds VII. The polarographic reduction of pyridine‐like heterocycles

Abstract

The polarographic reduction of pyridine-like heterocycles in 5 . 10-2 M tetraethy lammonium iodide in 95 % dimethylformamide gives well pronounced two-electron waves. Half-wave potentials of seven heterocyclic compounds have been determined in this medium. The data have been found to fit the correlation with energies of the lowest free. x-molecular orbitals in the HMO approximation. A similar correlation has also been obtained for half-wave potentials of some heterocycles taken from the literature.A number of polarographic works has been devoted to the study of half-wave reduction potentials of aromatic hydrocarbons and their derivatives in organic solvents. In this connection, Maccoll(3) and Lyons (4) have shown that there is a correlation between the energies of the lowest free Tc-molecular orbitals of aromatic hydrocarbons and (*) Presented at the symposium