LUMINESCENCE OF TRIS(2,2'-BIPYRIDINE)RUTHENIUM(2) DICHLORIDE

No previously published explanation of the luminescence of tris(2,2′-bipyridine)ruthenium(II) dichloride has been completely adequate in explaining all of the experimental data. Evidence is presented in this paper that supports assignment of the emission as charge-transfer, spin-forbidden luminescence. Spin-orbit coupling existing in the complex enhances the probability of singlet-triplet transitions and yields an abnormally shortlived phosphorescence. In an EPA solvent, the rate constants for phosphorescence, triplet internal conversion, singlet internal conversion, fluorescence, and intersystem crossing have been determined as kp = 2.9 × 105 sec−1, kic3 = 3.1 × 105 sec−1, kic1 = 5 × 108 sec−1, kf s 4 × 105 sec−1, and ix  5 × 1010 sec−1, respectively. © 1969, American Chemical Society. All rights reserved.