Thermal redistribution of energy from an excited [formula omitted] term to a nearby chemically reactive 3dd level in [Rh(III)(NN) 3](PF 6) 3 complexes

• Published in: Chemical physics letters Vol. 255; no. 4; pp. 445 - 450
• Main Authors: Brozik, J.A., Crosby, G.A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1996
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/0009-2614(96)00403-4

Below ∼ 150 K [Rh(NN) 3](PF 6) 3 complexes display 3gpπ ∗ phosphorescences characteristic of the NN diimine ligand [NN = 1,10-phenanthroline (phen) or 2,2′-bipyridine (bpy)]. Above ∼ 150 K and below the melting point of glycerol, a temperature-dependent first-order photoreaction occurs. Temperature dependencies of these photochemical reactions conform to the Arrhenius equation with activation energies in the 2–3 × 10 3 cm −1 range. These results are interpreted in terms of thermal redistribution from an excited 3ππ ∗ term to a nearby chemcially reactive 3dd manifold. The relationship of the Arrhenius activation energies to the electronic states of the parent complexes and the paths of intramolecular energy migration are discussed.