The initial characterization of all compounds is performed by 1D 1H and 13C NMR spectroscopy. For compounds that contain relevant heteroatoms, additionally, 31P, 19F, 15N and so on are performed as well. Multidimensional NMR spectroscopy is sometimes used for the thorough assignments of all the nuclei in a compound. Additionally, we use both multinuclear and multidimensional NMR spectroscopy for characterizing catalytic intermediates. Such measurements provide us with invaluable information regarding catalytic reaction mechanisms. We also sometimes use NMR spectroscopy for investigating paramagnetic compounds. Variable temperature NMR spectroscopy on paramagnetic compounds provide very useful information regarding spin state switching in solution.