title: Fine-tuning of biaryl dihedral angles: structural characterization of five homologous three-atom bridged biphenyls by X-ray crystallography.
abstract: The homologous series of three-atom bridged biaryls comprising 5,7-dihydro-1,2,3,9,10,11-hexamethoxydibenzo[c,e]oxepine, 6,7-dihydro-1,2,3,9,10,11-hexamethoxy-6-methyl-5H-dibenzo[c,e]azepinium chloride, 5,7-dihydro-1,2,3,9,10,11-hexamethoxydibenzo[c,e]thiepine, and the 6-oxide and 6,6-dioxide derivatives of the latter have been characterized by X-ray crystal structure analysis. Within this series the endocyclic and exocyclic biaryl dihedral angles vary over 10 degrees ranges, reflecting the changing balance of intramolecular (steric, geometric) and intermolecular (crystal packing) forces, the former being potential control elements for fine-tuning the helicity of the biaryl system.
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, England.
authors.forename: David J
authors.initials: DJ
authors.lastname: Edwards
authors.forename: Robin G
authors.initials: RG
authors.lastname: Pritchard
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Wallace
mesh_terms: D001713:Biphenyl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006572:Heterocyclic Compounds, Bridged-Ring / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D001713:Biphenyl Compounds; D006572:Heterocyclic Compounds, Bridged-Ring