Aquation

About: Aquation is a research topic. Over the lifetime, 1443 publications have been published within this topic receiving 17507 citations.

The contrasting chemistry and cancer cell cytotoxicity of bipyridine and bipyridinediol ruthenium(II) arene complexes

Abstract: The synthesis and characterization of ruthenium(II) arene complexes [(η6-arene)Ru(N,N)Cl]0/+, where N,N = 2,2′-bipyridine (bipy), 2,2′-bipyridine-3,3′-diol (bipy(OH)2) or deprotonated 2,2′-bipyridine-3,3′-diol (bipy(OH)O) as N,N-chelating ligand, arene = benzene (bz), indan (ind), biphenyl (bip), p-terphenyl (p-terp), tetrahydronaphthalene (thn), tetrahydroanthracene (tha) or dihydroanthracene (dha), are reported, including the X-ray crystal structures of [(η6-tha)Ru(bipy)Cl][PF6] (1), [(η6-tha)Ru(bipy(OH)O)Cl] (2) and [(η6-ind)Ru(bipy(OH)2)Cl][PF6] (8). Complexes 1 and 2 exibit CH (arene)/π (bipy or bipy(OH)O) interactions. In the X-ray structure of protonated complex 8, the pyridine rings are twisted (by 17.31°). In aqueous solution (pH = 2−10), only deprotonated (bipy(OH)O) forms are present. Hydrolysis of the complexes was relatively fast in aqueous solution (t1/2 = 4−15 min, 310 K). When the arene is biphenyl, initial aquation of the complexes is followed by partial arene loss. Complexes with arene =...

Iridium-based electrocatalytic systems for the determination of insulin.

Abstract: Two electrochemical catalytic systems for the determination of insulin were developed. The homogeneous system was based on the oxidation of insulin by chloro complexes of iridium(IV). Kinetic studies revealed that the aquation of iridium complexes activated them toward the oxidation of insulin in acidic solutions; e.g., the rate constant was equal to 25, 900, and 8400 L mol-1 s-1 for the oxidation of insulin by the IrCl62-, Ir(H2O)Cl5-, and Ir(H2O)2Cl4 complexes, respectively. The inertness of the iridium complexes argued for the outer-sphere mechanism of the homogeneous oxidation reaction. Electroplating of aquated iridium complexes on the glassy carbon electrode resulted in the formation of the iridium oxide (IrOx) surface film, which was used in the heterogeneous detection system for insulin. The catalytic activity of the IrOx film toward insulin oxidation was ascribed to a combination of electron-transfer mediation and oxygen transfer which was related to the acid/base chemistry of the film. The IrOx ...