Premium
Direct Spectroscopic Evidence of Hyperconjugation Unveils the Conformational Landscape of Hydrazides
Author(s) -
Gloaguen Eric,
Brenner Valérie,
Alauddin Mohammad,
Tardivel Benjamin,
Mons Michel,
ZehnackerRentien Anne,
Declerck Valérie,
Aitken David J.
Publication year - 2014
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201407801
Subject(s) - conformational isomerism , hyperconjugation , chemistry , computational chemistry , nitrogen atom , hydrazide , ramachandran plot , spectroscopy , gas phase , characterization (materials science) , stereochemistry , nanotechnology , molecule , organic chemistry , materials science , protein structure , group (periodic table) , physics , biochemistry , quantum mechanics
The stereochemistry of hydrazides makes them especially interesting as building blocks for molecular design. An exhaustive conformational analysis of three model hydrazides was conducted in a conformer‐selective approach by using a combination of high‐level quantum chemistry calculations and vibrational spectroscopy in the gas phase and in solution. The NH stretch frequency was found to be highly sensitive to hyperconjugation, thus making it an efficient probe of the conformation of the neighboring nitrogen atom. This property greatly assisted the identification of the isomers observed experimentally in the conformer pool. A rationalization of the hydrazide conformational landscape is proposed, therefore paving the way for a better characterization of secondary structures in larger systems.