Excited state behavior of tetrakis(2,2,6,6-tetramethyl-3,5-heptane-dionato)cerium(IV) - Emission and photoredox reaction from ligand-to-metal charge transfer states

The complex Ce-IV(tmhd)(4) with tmhd = 2,2,6,6-tetramethyl-3,5-heptane-dion ate anion is luminescent and photoreactive. It is suggested that the emissi on originates from a higher-energy ligand-to-metal charge transfer (LMCT) s tate and terminates at the lowest-energy LMCT state. This luminescence is t hus equivalent to the well-known metal-centered fluorescence of Ce(III) com pounds. In addition, LMCT excitation of Ce-IV(tmhd)(4) induces a reduction of Ce(IV) to Ce(III). (C) 2001 Elsevier Science B.V. All rights reserved.