Synthesis, coordination, and spectroscopic properties of 2,2 '-bipyridyldimesitylpalladium(II) and 6-mesityl-2,2 '-bipyridyldimesitylpalladium(II)

摘要

The synthetic route to the dimesitylpalladium(II) complex [(bpy)PdMes(2)] (1) (Mes = mesityl = 2,4,6-trimethyl phenyl) does not only give the desired compound but also the 6-mesityl-2,2'bipyridyldimesitylpalladium [(6-Mes-bpy)-PdMes(2)] (2) complex and the free ligand 6,6'-dimesityl-2,2'-bipyridine in reasonable yields. Single crystals of 2 were examined by X-Ray diffraction. The compound reveals a sterically crowded molecular structure. An intramolecular pi-stacking interaction was found between the mesityl substituent on the bipyridine ligand and the adjacent mesityl ligand. The electrochemical behaviour of 1 and 2 together with a related compound was examined at various temperatures showing two reversible reduction reactions and reversible one-electron oxidation steps at low temperatures. The latter are assigned to Pd-II/Pd-III couples. [References: 15]