Besides NMR spectroscopy, IR spectroscopy is extremely powerful for gaining structural information of molecules. Often this method is used as a simple characterization tool. However, we also use IR spectroscopy in combination with electrochemistry (IR spectroelectrochemistry). Such an approach allows us to gather structural information on chemical systems in their various redox states. IR spectroelectrochemistry also provides useful information on the charge distribution in molecules. Additionally, IR spectroelectrochemistry helps us in determining the donor properties of new redox-active ligands and in probing mechanisms of electrocatalytic reactions.