Tsun-Ren Chen

A new pyridylamine for blue light electroluminescent devices

The new pyridylamine, N , N ′-bis(1-naphthyl)- N , N ′-diphenyl-2,6-diaminopyridine (NPP), in which the nitrogen atoms form a linear array, was synthesized by the reaction of 2,6-dibromopyridine with N -phenyl-1-naphthylamine. This compound emits an intense blue color ( λ =443 nm, Φ f =0.74) upon irradiation by UV light and is suitable for use as an emitting layer in an electroluminescent device.

Structural characterization of copper complexes containing N,N′-di(6-methyl-2-pyridyl)formamidine

Abstract The reactions of N,N′-di(6-methyl-2-pyridyl)formamidine (HDMepyF) with copper halide produced complexes of the types CuCl2(HDMepyF) (1), Cu2X4(HDMepyF)2 (X=Cl, 2; X=Br, 3), Cu4I4(HDMepyF)2 (4), and [Cu2(HDMepyF)2](PF6)2 (5). All complexes were characterized by X-ray crystallography. The structure of 1 is tetrahedral with the Cu(II) center chelated by one HDMepyF ligand and coordinated by two chloride ligands. Complexes 2 and 3 are dinuclear complexes, in which the two Cu(II) centers are bridged by two halide atoms. Each Cu(II) metal center are also coordinated by one terminal halide atom and chelated by one HDMepyF ligand, forming a distorted square-pyramidal geometry. Complex 4 is tetranuclear with the four copper atoms forming a parallelogram and each Cu atom being in a three-coordination environment. One iodo atom and one HDMepyF ligand bridge two adjacent copper atoms. In complexes 1–4, the neutral HDMepyF ligands coordinate to the metal centers through one amine nitrogen atom and one adjacent pyridine nitrogen atom. In dinuclear complex 5, the HDMepyF ligands coordinate to the Cu(I) ions in a tridentate fashion, forming a chelating and a bridging bonding modes. The molecules of 5 are chiral due to the ligand constraints and each Cu atom forms a trigonal-planar geometry. All the HDMepyF ligands in complexes 1–5 adopt the s-cis, s-trans conformation.

Diiridium Bimetallic Complexes Function as a Redox Switch To Directly Split Carbonate into Carbon Monoxide and Oxygen

A pair of diiridium bimetallic complexes exhibit a special type of oxidation-reduction reaction that could directly split carbonate into carbon monoxide and molecular oxygen via a low-energy pathway needing no sacrificial reagent. One of the bimetallic complexes, Ir(III)(μ-Cl)2Ir(III), can catch carbonato group from carbonate and reduce it to CO. The second complex, the rare bimetallic complex Ir(IV)(μ-oxo)2Ir(IV), can react with chlorine to release O2 by the oxidation of oxygen ions with synergistic oxidative effect of iridium ions and chlorine atoms. The activation energy needed for the key reaction is quite low (∼20 kJ/mol), which is far less than the dissociation energy of the C═O bond in CO2 (∼750 kJ/mol). These diiridium bimetallic complexes could be applied as a redox switch to split carbonate or combined with well-known processes in the chemical industry to build up a catalytic system to directly split CO2 into CO and O2.

Water attack umpolung aromatic systems to release hydrogen.

The synthesis and structures of a series of cyclometalated iridium(III) complexes based on benzoxazole derivatives and triphenylphospine are reported. These complexes have a general formula (C^N)(2)Ir(Cl)(pph(3)) [where C^N is a monoanionic cyclometalating ligand, dfpbo = (difluorophenyl)benzoxazolato, pbo = 2-phenylbenzoxazolato, nbo = 2-(2-naphthyl)benzoxazolato, and pph(3) is a triphenylphospine ligand]. The complexes (dfpbo)(2)Ir(Cl)(pph(3)) (2a), (pbo)(2)Ir(Cl)(pph(3)) (2b), and (nbo)(2)Ir (Cl)(pph(3)) (2c) have been structurally characterized by X-ray crystallography. Complex 2a shows facile umpolung in the phenyl rings of the arylphosphine ligand and displays a catalytic propensity for water splitting.