Rhenium(I)-carbonyl compounds of di-2-pyridyl ketone: Electrochemical sensors for electrophiles and metal ions

The electrochemical behavior of fac-/cis-Re(CO)(2)(X)(dpk)Cl (dpk = di-2-pyridyl ketone and X = CO or PPh3) in the presence electrophiles and Group I and II metal ions are presented and the potential applications of these compounds as electrochemical sensors are demonstrated. In the case of electrophiles, the electrochemical responses are solvent dependent controlled by the nature of the electrophile and the rate of diffusion of electroactive species from the electrode surface. Fast diffusion leads to reactions at the metal center and a possible catalytic pathway, and a slow diffusion leads to reactions at the carbonyl group of coordinated dpk and a change in its coordination mode from bidentate to tridentate.