Infrared spectra and structure of carbanions : XIII. Dimeric dianions derived from α,β-diaryl-acrylonitriles

The IR spectra of the products of electrochemical and chemical (alkali metals, naphthalene anion-radical) reduction of substituted α,βdiaryl-acrylonitriles (32 compounds) were studied. It was found that the anion-radicals initially formed dimerize into the corresponding dimeric dianions. Correlation of v(CN) (dimeric dianions) with v(CN) (sodium methoxide adducts, ref 26), as well as with the σ^? constants of the substituents in the α-aromatic rings were found. The effects of the β-substituents, counter ions and solvents on v(CN) of the dimeric dianions are discussed.