title: Stereodynamics and edge-to-face CH-π aromatic interactions in imino compounds containing heterocyclic rings.
abstract: By comparison with close contact interactions between benzene rings there is a paucity of experimental data available for attractive interactions involving aromatic heterocyclic rings, especially for small molecules in solution. Herein we describe aromatic heterocyclic and carbocyclic edge-to face interactions and conformational stereodynamics of N-1,2-diphenylethyl imines bearing a phenyl group and either a 2-pyridyl, 3-pyridyl, 2-thiophene or 2-furanyl moiety on the imino carbon. X-ray crystal structures have been determined for two compounds. Slow rotation about the phenyl-imino bond in the E-isomers and around the heterocycle-imino bond in the Z-isomers of the pyridyl compounds was observed at low temperatures by NMR. Abnormally large shielding of one ortho hydrogen indicates that both the imino phenyl and heterocycle rings can engage in an edge-to-face interaction with the N-terminal phenyl moiety in the appropriate isomer. Some rotational barriers around the phenyl-imino and heterocycle-imino bonds were measured.
authors.affiliation: Departamento de Farmacia, Universidad CEU Cardenal Herrera, Avda. Seminario s/n, 46113, Moncada, Valencia, Spain. eugenia@uchceu.es.
authors.forename: M Eugenia
authors.identifier: http://orcid.org/0000-0002-3566-294X
authors.initials: ME
authors.lastname: González-Rosende
authors.affiliation: Departamento de Farmacia, Universidad CEU Cardenal Herrera, Avda. Seminario s/n, 46113, Moncada, Valencia, Spain. eugenia@uchceu.es.
authors.forename: Encarna
authors.initials: E
authors.lastname: Castillo
authors.affiliation: Department of Chemistry and Analytical & Biological Chemistry Research Facility, University College Cork, Cork, Ireland. brianj@ucc.ie.
authors.forename: W Brian
authors.initials: WB
authors.lastname: Jennings
authors.affiliation: School of Chemistry & Chemical Engineering, The Queen's University of Belfast, Belfast BT9 5AG, UK.
authors.forename: John F
authors.initials: JF
authors.lastname: Malone