Rhenium. Part II.* Polarographic Study of [ReO2py4]CI

The polarographic reduction of (ReO2py4]+ in KCl was studied using a dropping mercury cathode. The polarogram showed a single cathodic reduction wave at a half wave potential ,a —1.00 volt vs. S.C.E. at 28°. The reduction was reversible involving one electron. By measuring the half wave potentials as a function of different concentrations of free pyridine added, it was shown that in the reduced state the complex species contains two pyridine molecules