Iridium(III) complexes based on 5-nitro-2-(2′,4′-difluorophenyl)pyridyl: Syntheses, structures and photoluminescence properties

Acetylides for the Preparation of Phosphorescent Iridium(III) Complexes: Iridaoxazoles and Their Transformation into Hydroxycarbenes and N,C(sp3),C(sp2),O-Tetradentate Ligands

The preparation of three families of phosphorescent iridium(III) emitters, including iridaoxazole derivatives, hydroxycarbene compounds, and N,C(sp³),C(sp²),O-tetradentate containing complexes, has been performed starting from dimers cis-[Ir(μ²-η²-C≡CR){κ²-C,N-(MeC₆H₃-py)}₂]₂ (R = ^tBu (1a), Ph (1b)). Reactions of 1a with benzamide, acetamide, phenylacetamide, and trifluoroacetamide lead to the iridaoxazole derivatives Ir{κ²-C,O-[C(CH₂^tBu)NC(R)O]}{κ²-C,N-(MeC₆H₃-py)}₂ (R = Ph (2), Me (3), CH₂Ph (4), CF₃ (5)) with a fac disposition of carbons and heteroatoms around the metal center. In 2-methyltetrahydrofuran and dichloromethane, water promotes the C-N rupture of the IrC-N bond of the iridaoxazole ring of 3-5 to form amidate-iridium(III)-hydroxycarbene derivatives Ir{κ¹-N-[NHC(R)O]}{κ²-C,N-(MeC₆H₃-py)}₂{═C(CH₂^tBu)OH} (R = Me (6), CH₂Ph (7), CF₃ (8)). In contrast to 1a, dimer 1b reacts with benzamide and acetamide to give Ir{κ⁴-N,C,C',O-[py-MeC₆H₃-C(CH₂-C₆H₄)NHC(R)O]}{κ²-C,N-(MeC₆H₃-py)}(R = Ph (9), Me (10)), which bear a N,C(sp³),C(sp²),O-tetradentate ligand resulting from a triple coupling (an alkynyl ligand, an amide, and a coordinated aryl group) and a C-H bond activation at the metal coordination sphere. Complexes 2-4 and 6-10 are emissive upon photoexcitation, in orange (2-4), green (6-8), and yellow (9 and 10) regions, with quantum yields between low and moderate (0.01-0.50) and short lifetimes (0.2-9.0 μs).

Synthesis, crystal structure and Hirshfeld surface analysis of [bis-(di-phenyl-phosphan-yl)methane-κP]chloridobis-[2-(pyridin-2-yl)phenyl-κ2 N,C 1]iridium(III)

The title IrIII complex, [Ir(C11H8N)2Cl(C25H22P2)], was synthesized from the substitution reaction between the (ppy)2Ir(μ-Cl)2Ir(ppy)2 (ppy = deprotonated 2-phenyl-pyridine, C11H8N-) dimer and 1,1-bis-(di-phenyl-phosphan-yl)methane (dppm, C25H22P2) under an argon gas atmosphere for 20 h. The IrIII atom is coordinated by two C,N-bidentate ppy anions, a unidentate dppm ligand and a chloride anion in a distorted octa-hedral IrC2N2PCl arrangement. The N donor atoms of the ppy ligands are mutually trans while the C atoms are cis. Intra-molecular aromatic π-π stacking between the phenyl rings of ppy and dppm, and C-H⋯Cl inter-actions are observed. In the crystal, C-H⋯Cl and C-H⋯π contacts link the mol-ecules into a three-dimensional network. A Hirshfeld surface analysis was carried out to further qu-antify the inter-molecular inter-actions, and indicated that H⋯H contacts (63.9%) dominate the packing.

Polynuclear cage-like Au(i) phosphane complexes based on a S2− template: observation of multiple luminescence in coordinated polyaromatic systems

Sulfido-phosphane Au(i) complexes display multiple emissions, the nature of which is determined by the distance between Au(i) and the chromophoric center.