The electrochemical detection of Ru(II) in a methyl methacrylate solution

This article describes the voltammetric behaviour of RuCl2(PPh3)3 in a methyl methacrylate (MMA) solution. Acquiring this type of information is only possible when the ohmic resistance can be kept sufficiently low. Therefore, the conductivity study of pure methyl methacrylate and a tetrabutylammonium tetrafluoroborate (TBABF4) methyl methacrylate solution has been described as well. Impedance measurements show an increase in conductivity by adding TBABF4, while a conductometric curve illustrates the presence of ion pairs, triple ions and quadrupoles depending on the TBABF4 concentration. The conductivity of a 0.1 mol L−1 TBABF4–MMA solution (formation of charged triple ions) was high enough to perform electrochemical experiments and a calibration curve could be obtained. The ability of obtaining relevant electrochemical data in low conducting media opens up new perspectives, especially for electroanalytical purposes used to monitor polymer reactions, more specific atom transfer radical polymerization (ATRP) reactions. This method employs a redox process with transition metal complexes in which a halogen ion is transferred reversibly between the transition metal and the polymer chain end. The dynamic equilibrium can be monitored by measuring the ruthenium concentration.