Proton-linked bi- and tri-metallic gold cyanide complexes observed by ESI-MS spectrometry

• Published in: Journal of inorganic biochemistry 2008-03, Vol.102 (3), p.576-583
• Main Authors: Yangyuoru, Philip M., Webb, James W., Shaw, C.F.
• Format: Article
• Language: English
• Subjects: Cyanates - chemistry; Cyanide; Electrospray ionization mass spectrometry; Gold - chemistry; Gold Compounds - chemistry; Gold(I); Gold(III); Hydrogen-Ion Concentration; Proton-linked; Spectrometry, Mass, Electrospray Ionization - methods
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/j.jinorgbio.2007.10.020

Electrospray ionization spectra of potential cyanide-containing gold-drug metabolites revealed additional, weak, unanticipated peaks at approximately twice the mass of the gold(I) and gold(III) cyanide complexes. The exact masses correspond to proton-linked bimetallic complexes, [H{Au(CN) m } 2] −, ( m = 2,4). Further investigation revealed a total of 12 examples, including trimetallic complexes, [H 2{Au(CN) m } 3] −; mixed species with two complexes, [H{Au(CN) 2}{Au(CN) 4}] −; and thiolato species, [H{(RS)Au(CN) 3} 2] −. trans-[AuX 2(CN) 2Cl 2] − and trans-[AuX 2(CN) 2Br 2] − generated 35Cl/ 37Cl and 79Br/ 81Br isotopic patterns for the protonated bi- and tri-metallic analogues which were in good agreement with the presence of four or six halide ligands, respectively. Concentration-dependent studies demonstrated that the signals are independent of the solution concentrations of mono-metallic precursors, suggesting formation in the gas phase during or following droplet desolvation.