| Abstract |
The role of substituents on resonance assisted hydrogen bonding (RAHB) vs. intermolecular hydrogen bonding is highlighted in known arylhydrazones of active methylene compounds (AHAMCs) and in their new representatives - (E/Z)-2-(2-(para-substitutedphenyl) hydrazineylidene)-N,N-diethyl-3-oxobutanamides (-C2H5, -H, -COOH, -CN). The strength of the H-bond depends on the attached functional groups to both the active methylene fragment and the aromatic moiety of the AHAMC. For instance, attachment of the strong electron donor group -N(C2H5)(2) (sigma(p) = -0.72) to the active methylene fragment of AHAMC allows to isolate this class of compounds without RAHB but with strong intermolecular H-bonds, which are the first examples reported herein. |
