Metal-Containing Amphiphiles: Orthometallated Iridium(III) Complexes with Substituted 6′-Phenyl-2,2′-bipyridines

Abstract

The reaction of 4′‐functionalized 6′‐phenyl‐2,2′‐bipyridine ligands (L‐n) with the dimer [(ppy)2IrCl]2 (ppy = 2‐phenylpyridine anion) and subsequent counterion exchange affords a new series of cationic orthometallated iridium(III) complexes, [(ppy)2Ir(L‐n)][PF6] (1–5), which have been characterized by spectroscopic methods. These complexes have a large shape anisotropy and significant amphiphilic character. The crystal structure of 4 has been determined by X‐ray diffraction.

New heteroleptic cyclometalated iridium(III) complexes containing 2-(2′,4′-difluorophenyl)-4-methylpyridine for organic light-emitting diode applications

“…The N-Ir-N angles in these complexes were between 1711 and 1751 with the Ir-C bond lengths of (dfpmpy) 2 Ir(ppc) [ [38,39] and the mononuclear complexes containing the Ir(ppy) 2 fragments [40], but longer than the bis-cyclometalated acac complexes [1,36]. The basicity of the nitrogen atom in pyrazine carboxylate (pK a ¼2.76) [41] and pipecolinic acid (pK a ¼2.77) [42] was reported to be similar, but the s-bond between the iridium metal ion and the nitrogen atom in (dfpmpy) 2 Ir(prz) [Ir-N(prz) ; 2.133Å] is stronger than that in (dfpmpy) 2 Ir(ppc) [Ir-N(ppc); 2.209Å].…”

Synthesis and characterization of blue phosphorescent cyclometalated Ir(III) complexes containing 2-(imidazol-2-yl)pyridine as ancillary ligand

“…The complex has distorted octahedral coordination geometry around iridium atom and the two nitrogen atoms of f2ppy ligands exhibit cis-C-C and trans-N-N chelate dispositions. The Ir-C1 bond of the complex is shorter than that of Ir-N (Ir-N1 and Ir-N2), that is similar to the values of complexes with the ''Ir(acac)'' fragment [19,21,22], but Ir-C12 bond is almost equal to that of Ir-N (Ir-N1 and Ir-N2) due to the steric hindrance ancillary ligand 2-(imidazol-2-yl)pyridine. The Ir-N3 bond is 2.118(9)Å, which belongs to s bond, is shorter than that of Ir-N5 (2.154(8)Å).…”

“…The Ir-N3 bond is 2.118(9)Å, which belongs to s bond, is shorter than that of Ir-N5 (2.154(8)Å). All other features for the complex appear to be analogous to previous reports on similar types of complexes [21,22].…”

Determination of the relative ligand‐binding strengths in heteroleptic IrIIIcomplexes by ESI‐Q‐TOF tandem mass spectrometry

“…Because of their promising photophysical behavior, ionic character and good solubility in polar organic solvents or even in aqueous media, cationic iridium(III) complexes have gained much interest in recent years; applications as emissive materials in light‐emitting electrochemical cells (LECs), biolabeling/bioimaging, sensing as well as photocatalysis have been established. The Neve group introduced a synthetic protocol that is today the most commonly used concept to synthesize cationic bis ‐cyclometalated Ir III polypyridyl complexes . Using this procedure, a broad range of 2,2′‐bipyridine, 1,10‐phenanthroline and 2,2′ : 6′,2″‐terpyridine derivatives has found use as neutral bidendate ligands .…”