Evidence of an nN(amide) → π*Ar Interaction in N-Alkyl-N,N′-diacylhydrazines
1,2-Dibenzoyl-1-tert-butylhydrazine (RH-5849) and related N-alkyl-N,N'-diacylhydrazines are environmentally benign
insect growth regulators. In this work, we show that an unusual nN(amide) → π*Ar interaction mediated by a hydrazide
amide nitrogen atom plays a crucial role in stabilizing their biologically active trans-cis (t-c) rotameric
conformations. We provide NMR and IR spectroscopic evidence for the presence of these interactions, which is also
supported by X-ray crystallographic and computational studies.