Structure, electron-accepting properties, and reactivity of nitrostilbenes

Nitrostilbenes, nitrostyrenes, nitrotoluenes, and nitrodibenzyls in neutral, radical anion, and dianion forms are studied by quantum chemical, electron spectroscopy, ESR spectroscopy, and cyclic voltammetry methods. The calculated electron affinities of nitroarenes are compared with electrochemical reduction potentials. The dianion form of stilbene is stable provided that it has two nitro groups in the para-position of the benzene ring. Nitrodibenzyls are converted to the corresponding nitrostilbenes by electrochemical reduction;this is explained by dissociative cleavage of C−H bonds in the trianion radical form of dibenzyl. In reactions of nitroarenes with bases, regioselectivity is determined by spin density distribution and by the conformation composition of the radical anions. Translated fromZhurnal Struktumoi Khimii, Vol. 39, No. 4, pp. 640–654, July–August, 1998.