title: NMR and quantum chemical analysis of 3-(2-methly-2-phenylhydrazinyl)cyclohex-2-en-1-one.
abstract: Two-dimensional representation of a molecular structure is in some cases misleading, since it may not correctly represent important details and may not provide adequate information on the electronic structure of the molecule. In such cases the physical-chemical properties of the molecule will not be properly interpreted on the basis of the molecular formula. For example, the NMR spectrum will differ significantly from what would be intuitively expected on the basis of this formula and one can deduce the correct electronic and steric structure of the molecule from the obtained spectra instead. In this article the NMR and quantum chemical analysis of the title compound 3-(2-methly-2-phenylhydrazinyl)cyclohex-2-en-1-one will be presented. The unusual NMR spectra and surprising protonation site of this compound will be explained based on the delocalization of the π-symmetric orbitals of its molecules. The proposed electronic structure and the observed but unexpected physical-chemical properties have been confirmed by quantum chemical calculations.
authors.affiliation: Chemical Works of Gedeon Richter Plc, API Research and Development - Spectroscopic Research (NMR Laboratory), Budapest, Hungary, zsofia.dubrovay@ximo-inc.com.
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Dubrovay
authors.forename: Péter G
authors.initials: PG
authors.lastname: Szalay
mesh_terms: D003198:Computer Simulation; D003512:Cyclohexanones / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D011522:Protons; D011789:Quantum Theory; D013329:Structure-Activity Relationship
chemical_list: C000602056:3-(2-methly-2-phenylhydrazinyl)cyclohex-2-en-1-one; D003512:Cyclohexanones; D006834:Hydrazines; D011522:Protons