title: Direct spectroscopic evidence of hyperconjugation unveils the conformational landscape of hydrazides.
abstract: 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.
authors.affiliation: CNRS, CEA, LIDyL, Laboratoire Francis Perrin URA 2453, 91191 Gif-sur-Yvette (France) http://iramis.cea.fr/Pisp/70/eric.gloaguen.html. eric.gloaguen@cea.fr.
authors.forename: Eric
authors.initials: E
authors.lastname: Gloaguen
authors.forename: Valérie
authors.initials: V
authors.lastname: Brenner
authors.forename: Mohammad
authors.initials: M
authors.lastname: Alauddin
authors.forename: Benjamin
authors.initials: B
authors.lastname: Tardivel
authors.forename: Michel
authors.initials: M
authors.lastname: Mons
authors.forename: Anne
authors.initials: A
authors.lastname: Zehnacker-Rentien
authors.forename: Valérie
authors.initials: V
authors.lastname: Declerck
authors.forename: David J
authors.initials: DJ
authors.lastname: Aitken
mesh_terms: D001386:Azides / Q000737:chemistry*; D008968:Molecular Conformation; D011789:Quantum Theory; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D001386:Azides
keywords: IR spectroscopy; hydrazides; hyperconjugation; laser spectroscopy; structure elucidation