title: Nitrile ylides: allenic and propargylic structures from pyrazinylnitrenes. Experimental and theoretical characterization.
abstract: Matrix photolysis of 2-pyrazinyl azides/tetrazolo[1,5-a]pyrazines generates nitrile ylides 15 via pyrazinylnitrenes 13 and triazacycloheptatetraenes 14. The nitrile ylides 15 are characterized by IR spectroscopy in conjunction with harmonic and anharmonic vibrational frequency calculations. The nitrile ylides exist in the matrices in the Z,Z-conformations in which they are born. Substitution on the nitrile carbon of nitrile ylides has a profound effect on their structure. Even different conformers of the same molecule can have differences up to 200 cm(-1) in the IR absorptions of the ylide moieties. Nitrile ylides 15a and 15b (R = H or Cl, R' = H) have allenic structures (15 Allenic). Nitrile ylide 15c (R = R' = CH3) has a distinctly propargylic structure (15 Propargylic) in the experimentally observed Z,Z-conformation.
authors: Institut des Sciences Analytiques et de Physico-Chimie pour l'Environnement et les Matériaux, Equipe Chimie Physique, UMR 5254, Université de Pau et des Pays de l'Adour , Pau 64000, France.
authors: Didier
authors: D
authors: Bégué
authors: Chris
authors: C
authors: Addicott
authors: Riko
authors: R
authors: Burgard
authors: Pawel
authors: P
authors: Bednarek
authors: Emilie
authors: E
authors: Guille
authors: Isabelle
authors: I
authors: Baraille
authors: Curt
authors: C
authors: Wentrup