Electrochemistry of Icosahedral Metal Full and Half Sandwich Metallacarboranes in Phosphate Buffers

Abstract

Electrochemical behavior of metallacarboranes containing different central coordination atoms – Co, Cr, Ni and Fe – in aqueous phosphate buffers is described in this study. Also, the effects of number of the dicarbaborane ligands present in the metallacarborane and the influence of mixed or polydecker sandwich structure on the electrochemical activity were studied. In general, we found two distinctive regions of electrochemical activity. One of them is located in the negative potential range and corresponds to redox process on the central metal atom. The second one is located in the positive potential region and is connected to core cage oxidation pro- cess. The results revealed clearly promising properties of majority of studied metallacarboranes to be used as electrochemical tags in aqueous solutions, with potentially better properties that the known and widely studied cobalt bis(dicarbollide)(1-) ion based systems.