Evidence for multiple-state emission from ruthenium(II) complexes

Temperature dependence measurements (2–77°K) of both the lifetime of decay and the quantum yield of luminescence for the tris(2,2′-bipyridine)ruthenium(II) cation show the emission to originate from several levels. Energy level gaps, rate constants, and quantum yields have been measured for each individual level, and group theoretical symmetry assignments have been made on the basis of a proposed electronic coupling model.