Luminescent properties of tris(2,2′-bipyridine) dichloro ruthenium(II) hexahydrate under high pressure

Abstract

The luminescence properties of tris(2,2′-bipyridine) dichloro ruthenium(II) hexahydrate ([Ru(bpy)3]2+ Cl2·6H2O) were studied with a diamond anvil cell (DAC) under quasi-hydrostatic pressure. The emission intensity increases with elevated pressure and the fluorescence maxima was observed at 1.7 GPa. The emission intensity then drops down with further compression. The emission peak position shift to higher energy side (blue shift) firstly, and then shift to lower energies (red shift) at pressures above 1.4 GPa. Two phase transitions occur at about 1.4 and 6.6 GPa. The emission almost quench at 10.4 GPa. This behavior may be due to the reduction of Ru ion coordination number; the 2,2′-bipyridine molecules are isolated from [Ru(bpy)3]2+ and thus influence the emission properties.