Symmetrically bifurcate hydrogen bonding. Part I. Bis-(β-acylvinyl)-amines

Abstract

Symmetrically bifurcate three-centre hydrogen bonding, N–[graphic omitted], was found in the symmetrical cis,cis-form of several bis-(β-acylvinyl)amines, [R¹C(O)CR²CR³]₂NH. The alternative cis,trans–s-cis and cis,trans–s-trans-structures were also detected in amounts depending on the size of the R-alkyl substituent, the solvent, and its concentration. The data do not prove conclusively that the hydrogen bond is truly symmetrically forked.