| The oxidative behavior of Auranofin, 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranosato-S(triethylphosphine)gold(I), was investigated by using cyclic voltammetry (CV) in 0.1 M Bu4NBF 4/CH2Cl2 and 0.1 M Bu4NPF6/CH 2C12 solutions using Pt working and auxiliary electrodes and a Ag/AgCl reference. CV studies at scan rates from 50--2,000 mVs -1 and Auranofin concentrations between 1 and 4 MM, show two irreversible oxidation processes occurring at + 1.1 V and + 1.6 V vs. Ag/AgCl.;Treatment of Auranofin with the one electron oxidizing agent [Cp 2Fe]PF6 gave a mu-thiolato digold cluster, [(Et3PAu) 2(mu-SR)]22+ and the disulfide, bis(tetraacetlythioglucose). A mechanism for Auranofin oxidation is proposed on the basis of chemical and electrochemical studies. The mu-thiolato species is also obtained by treatment of Auranofin with Et3PAuNO3 in CH3CN or addition of methanolic silver nitrate to an equimolar mixture of Auranofin and Et 3PAuCl followed by product isolation. The X-ray structure is reported for the Auranofin analogue, [Au4(PMe3)4(thioglucose) 2](NO3)2. The structure of the cluster confirms the coordination of two Me3PAu+ to a bridging thiolato moiety and the two-thiolates are on opposite sides and trans to each other. The gold-gold distances are Au1-Au2 = 3.106(7), Au1-AuA = 3.171(11), and Au2-Au2A = 3.144(12)A.;The cyclic voltammetry of Solganol, aurothioglucose, was investigated in 0.5 M NaClO4/H2O solutions using a three-electrode system consisting of a platinum working electrode, a platinum-wire auxiliary electrode, and a silver-silver chloride reference electrode. A broad peak obtained at +1.2 V, which affected by scan rate and pH changes. Multiple CV scans of Solganol showed an enhancement in current due to a possible filming on the electrode surface. Bulk electrolysis of Solganol showed n = 2. Chemical oxidation using [CP2Fe]PF6 showed no change in the NMR peaks and there was no change in the color of the mixture. Based on bulk electrolysis, resistance to chemical oxidation, and pH studies, the peak at +1.2 V vs Ag/AgCl was assigned as AuI/III.;A series of binuclear Au(I) halide and thiolate complexes (AUX) 2dppbz (X = Cl, Br, I, p-SC6H4CH 3) were synthesized. All of the newly synthesized complexes gave satisfactory elemental analysis and characterized by 1H and 31P NMR. The complex (AuCl)2dppbz crystallized in the orthorhombic space group Pbca with a = 16.955(3), b = 18.160(2), c = 22.225(1) A, alpha = beta = gamma = 90°, Z = 8 (at 293 K). The Au...Au bond length of 2.99 A is in the range of gold-gold interaction distance. |
