A joint electrochemical/ spectroelectrochemical inspection (and re-inspection) of high-nuclearity platinum carbonyl clusters

The accurate study of the electron transfer activity of the tetraanion [Pt(19)(CO)(22)](4-) is presented together with that of the dianion [Pt(38)(CO)(44)](2-), which was previously studied by spectroelectrochemistry but only partially examined from the electrochemical viewpoint. The main feature of the two clusters is that they undergo a sequence of close-spaced pairs of reversible one-electron processes, which are qualitatively reminiscent of those exhibited by the dianion [Pt(24)(CO)(30)](2-). In order to focus on such unique aspect of the three structurally characterised platinum clusters, we have investigated (and reinvestigated) their electrochemical and spectroelectrochemical redox properties, also reporting on the electron paramagnetic resonance (EPR) spectrum of the monoanion [Pt(24)(CO)(30)](-), which represents the first successful study of the paramagnetism of homoleptic platinum-carbonyl clusters.