Graphene-supported organoiridium clusters catalyze -alkylation of amines hydrogen borrowing reaction.

Graphene-supported organic iridium clusters (GSOICs) have been designed, prepared, characterized, and used for -alkylation of amines hydrogen borrowing reactions. Structural analysis data (including IR, XPS, TEM and EDS) show that organoiridium clusters are uniformly formed on the surface of graphene, and the grain size of GSOIC is between 1 and 3 nm. After being activated by the auxiliary ligand TMPP (tris(4-methoxyphenyl)phosphine), GSOIC showed excellent catalytic performance for hydrogen borrowing reaction, with its turnover frequency (TOF) reaching 13.

Ligand effect of cyclometallated iridium(iii) complexes on -alkylation of amines in hydrogen borrowing reactions.

Dinuclear iridium complexes with the general formula (C^N)Ir(μ-Cl)Ir(C^N) (C^N = bidentate ligand with carbon and nitrogen donor atoms) were prepared and used in catalytic systems for -alkylation of amines through the hydrogen borrowing pathway. Triphenylphosphine derivatives were used as auxiliary in catalytic systems to provide excellent conversion of amines to -alkylation products in yields ranging from 57% to 100%. The catalytic ability of the catalyst depends on the structure of its coordination ligands, including bidentate ligands (C^N) and triphenylphosphine derivatives.

A reduced graphene oxide-supported iridium nanocatalyst for selective transformation of alcohols into carbonyl compounds via a green process.

A nanocatalyst constructed from reduced graphene oxide and iridium atoms (RGOIrNc) showed high selectivity (99%-100%) and reliability for the transformation of aromatic alcohols into carbonyl compounds via ultrasonication without using harmful chemicals and solvents. Experimental data including Fourier transform infrared spectroscopy, x-ray diffraction, spherical-aberration-corrected field emission transmission electron microscopy and Raman spectra confirmed the nanostructure of the RGOIrNc. Noticeably, the structural characteristics of this catalyst remained unchanged within 25 catalytic cycles and the activity and selectivity for the transformation of benzylic alcohols showed good stability.

Graphene oxide-iridium nanocatalyst for the transformation of benzylic alcohols into carbonyl compounds.

A catalyst constructed from graphene oxide and iridium chloride exhibited high activity and reliability for the selective transformation of benzylic alcohols into aromatic aldehydes or ketones. Instead of thermal reaction, the transformation was performed under ultrasonication, a green process with low byproduct, high atomic yield and high selectivity. Experimental data obtained from spherical-aberration corrected field emission TEM (ULTRA-HRTEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy and Raman spectra confirm the nanostructure of the title complex.

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.

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.

An 18+δ iridium dimer releasing metalloradicals spontaneously.

Reductive elimination of a bridged chlorine from a diiridium(iii) core, [(dfpbo)(2)Ir(μ-Cl)](2) (dfpbo = 2-(3.5-difluorophenyl)benzoxazolato-N,C(2)), afforded an iridium dimer, [(fpbo)(2)Ir](2)(μ-Cl), showing an 18+δ structure with a bent bridge, which can release metalloradicals spontaneously in solution at room temperature.

A novel cyclometalated dimeric iridium complex, [(dfpbo)2Ir]2 [dfpbo = 2-(3,5-difluorophenyl)benzoxazolato-N,C2'], containing an unsupported Ir(II)-Ir(II) bond.

An unusual iridium complex, [(dfpbo)(2)Ir](2) [dfpbo = 2-(3,5-difluorophenyl)benzoxazolato-N,C(2')], which is the first dimeric iridium complex composed of two bis-cyclometalated Ir(II) structures connected by an unsupported Ir(II)-Ir(II) bond, has been synthesized and fully characterized. Under mild conditions of neutral pH at room temperature, this complex dissociated spontaneously to form the stable radical [Ir(dfpbo)(2)]*.

Crystal structures and solution behaviors of dinuclear d(10)-metal complexes containing anions of N,N'-bis(pyrimidine-2-yl)formamidine.

The salts of Zn(II), Cd(ii) and Hg(II) react instantaneously with Kpmf (pmf(-) = anion of N,N'-bis(pyrimidine-2-yl)formamidine, Hpmf) in THF, producing bimetallic complexes of the types [M(2)(pmf)(3)](X) (M = Zn(II), X = I(3)(-), ; M = Zn(II), X = NO(3)(-), ; M = Zn(II), X = ClO(4)(-), ; M = Cd(II), X = NO(3)(-), ; M = Cd(II), X = ClO(4)(-), ) and Hg(2)(pmf)(2)X(2) (X = Cl, ; Br, ; I, ). New tridentate and tetradentate coordination modes were observed for the pmf(-) ligands and their fluxional behaviors investigated by measuring variable-temperature (1)H NMR spectra. Complexes and , which possess only tetradentate coordination modes for the pmf(-) ligands in the solid state show larger free energy of activation (DeltaG(c)( not equal)) for the exchange than complexes and with tetradentate and/or tridentate coordination modes.