title: Structural studies of some push-pull N-arylbenzazoles.
abstract: X-Ray crystal structures, and calculated structures (at B3LYP/6-31G level) are reported for seven N-arylbenzazoles (two carbazoles, indoles and benzimidazoles, and one indazole) bearing electron withdrawing groups in the 2-position of the N-aryl ring. The structures are markedly non-planar by rotation around the N-aryl bond, with the substituent in most cases lying s-E in relation to the N-aryl bond; intermolecular electrostatic interactions in the crystal rationalise the two examples in which an s-Z conformation is observed. A large interplanar angle between the benzazole and the N-aryl planes is associated with a small interplanar angle between the planes of the N-aryl group and the substituent and vice versa.
authors.affiliation: School of Chemistry, The University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ UK.
authors.forename: Lynne A
authors.initials: LA
authors.lastname: Crawford
authors.forename: Maria
authors.initials: M
authors.lastname: Ieva
authors.forename: Hamish
authors.initials: H
authors.lastname: McNab
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry*; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D007191:Indazoles / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D001562:Benzimidazoles; D007191:Indazoles; D007211:Indoles