Synthesis, structures, and properties of iridium(III) bis-cyclometallated complexes containing three-atom chelates

Crystal structure of the phosphorescent complex diethyldithiophosphonato-κ2 S,S′-bis(2-phenylpyridinato-κ2 C,N)iridium(III), C26H26N2O2PS2Ir

C26H26N2O2PS2Ir, orthorhombic, P212121 (no. 19), a = 9.4097(6) Å, b = 13.2837(9) Å, c = 20.6400(14) Å, V = 2579.9(3) Å3, Z = 4, R gt(F) = 0.0202, wR ref(F 2) = 0.0471, T = 293(2) K.

A lab-on-a-molecule for anions in aqueous solution: using Kolbe electrolysis and radical methylation at iridium for sensing

Iridium complex [(pq)(2)IrCl](2) (1) is established as a quantitatively operating lab-on-a-molecule in aqueous media at physiological pH. Acting as a chemodosimeter, 1 uses two channels, PL and ECL, for the detection of cyanide and acetate, with the former undergoing nucleophilic attack and the latter Kolbe electrolysis and radical-metal combination.

Two closely related iridium(III) complexes as colorimetric and fluorometric chemodosimeters for nitrite in aqueous solution operating along different modes of action

Two closely related dual-channel chemodosimeters for nitrite in buffered aqueous acetonitrile were developed using [(pq)(2)IrCl](2) (1) and [(ppy)(2)IrCl](2) (2). In the UV-vis channel, the addition of nitrite caused visibly distinct color changes with both probes as a result of sizable absorption intensity enhancements. In the photoluminescence channel, the probes behaved oppositely upon the addition of nitrite. The emission was increased with 1, while it was quenched with 2. NMR and X-ray studies indicated that structurally very different η(1)-nitrito-N and η(2)-nitrito-O,O' complexes were formed. Linear relationships for the quantification were obtained in both channels, allowing one to analyze for NO(2)(-) in a range from 5 × 10(-5) to 2 × 10(-2) M.

Bimetallic N-heterocyclic carbene-iridium complexes: investigating metal-metal and metal-ligand communication via electrochemistry and phosphorescence spectroscopy

Bimetallic [Ir(COD)Cl] and [Ir(ppy)(2)] (COD = 1,5-cyclooctadiene; ppy = 2-phenylpyridyl) complexes bridged by 1,7-dimethyl-3,5-diphenylbenzobis(imidazolylidene) (1), in addition to their monometallic analogues supported by 1-methyl-3-phenylbenzimidazolylidene (2), were synthesized and studied. Electrochemical analyses indicated that 1 facilitated moderate electronic coupling between [Ir(COD)Cl] units (DeltaE = approximately 60 mV), but not [Ir(ppy)(2)]. The metal-based oxidation potentials for the bimetallic complexes were within 20 mV of those for their monometallic analogues. Furthermore, spectroscopic analyses of the [Ir(ppy)(2)] bimetallic and monometallic complexes revealed nearly identical phosphorescence profiles, indicating that carbene coordination does not affect the energy of the emissive states. Collectively, these results suggest that N-heterocyclic carbenes (NHCs) such as 1 could link together two emissive fragments without altering their fundamental phosphorescence profiles. Ultimately, employing multitopic NHCs as non-interfering molecular connectors could facilitate the rational design of new phosphorescent materials as well as second-generation phosphor dopants.