THE N.M.R. SPECTRA AND CONFORMATION OF BUTADIENE DERIVATIVES

Abstract

The N.M.R. spectra of several butadiene derivatives have been analyzed using the computer program LAOCOON II. The molecules studied include the halogenated compounds fluoroprene, chloroprene and the three 1,4-dichlorobutadienes (cis, cis; trans, trans and cis, trans). The nuclear magnetic parameters, in particular the (H,H) coupling constants, have been compared with values for related compounds from the literature in order to see if an appreciable proportion of any of the molecules exist in a conformation other than the s-trans. It is concluded that this is not so for the halogenated butadienes listed above. The effectiveness of this technique for determining conformation for this class of molecule will be discussed.