title: Tuning the excited state of water-soluble Ir(III)-based DNA intercalators that are isostructural with [Ru(II)(NN)2(dppz)] light-switch complexes.
abstract: The synthesis of two new Ir(III)  complexes which are effectively isostructural with well-established [Ru(NN)2(dppz)](2+) systems is reported (dppz=dipyridophenazine; NN=2,2'-bipyridyl, or 1,10-phenanthroline). One of these Ir(III) complexes is tricationic and has a conventional N6 coordination sphere. The second dicationic complex has a N5C coordination sphere, incorporating a cyclometalated analogue of the dppz ligand. Both complexes show good water solubility. Experimental and computational studies show that the photoexcited states of the two complexes are very different from each other and also differ from their Ru(II) analogues. Both of the complexes bind to duplex DNA with affinities that are two orders of magnitude higher than previously reported Ir(dppz)-based systems and are comparable with Ru(II)(dppz) analogues.
authors.affiliation: Department of Chemistry, University of Chemistry, Sheffield (UK).
authors.forename: Sasha
authors.initials: S
authors.lastname: Stimpson
authors.forename: Dan R
authors.initials: DR
authors.lastname: Jenkinson
authors.forename: Andrew
authors.initials: A
authors.lastname: Sadler
authors.forename: Mark
authors.initials: M
authors.lastname: Latham
authors.forename: Ashley
authors.initials: A
authors.lastname: Wragg
authors.forename: Anthony J H M
authors.initials: AJ
authors.lastname: Meijer
authors.forename: Jim A
authors.initials: JA
authors.lastname: Thomas
mesh_terms: D004247:DNA / Q000737:chemistry*; D007364:Intercalating Agents / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008027:Light; D012413:Rubidium / Q000737:chemistry*
chemical_list: D007364:Intercalating Agents; D007495:Iridium; D004247:DNA; D012413:Rubidium
keywords: DNA; cyclometalation; intercalation; iridium; luminescence