title: 1,4,5,8,9,12-Hexamethyltriphenylene. A molecule with a flipping twist.
abstract: The synthesis and characterization of 1,4,5,8,9,12-hexamethyltriphenylene (5) is described. In the solid state, X-ray crystallographic studies reveal that compound 5 presents a highly distorted C2 geometry with a 53 degrees end-to-end twist. In solution, variable-temperature 1H NMR studies and molecular modeling present a story of rapid dynamic conformational interconversions between two C2 enantiomers (with a low activation barrier) and a slower C2-D3 interconversion (with a relatively high barrier)--the first time clear evidence of conformational interchange for these hindered triphenylenes has been provided. Further studies have established that 5 is a fluorescent stable blue emitter, and that the compound undergoes an irreversible one-electron electrochemical oxidation. Calculations have predicted this to be a radical cation of C2 geometry with 60 degrees end-to-end twist.
authors.affiliation: School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, U.K.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Stretton
authors.forename: Mark C
authors.initials: MC
authors.lastname: McConnell
authors.forename: Peter A
authors.initials: PA
authors.lastname: Wood
authors.forename: Simon
authors.initials: S
authors.lastname: Parsons
authors.forename: John B
authors.initials: JB
authors.lastname: Henry
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Mount
authors.forename: Trent H
authors.initials: TH
authors.lastname: Galow