A 13C NMR Study of 1,4-Diphenyl- and 1,1,4,4-Tetraphenyl-1,3-butadiene Dianions
Lithium, sodium, and potassium salts of the title dianions were investigated by means of 13C NMR spectroscopy in THF or DME at room temperature. The structures of the butadiene carbon skeleton and especially the behaviors of the α- and β-carbons caused by the conversion of the precursors into the dianions were reported together with the counter-cation effects.