Charge-Transfer Processes in (4-Nitrobenzoate)Re(CO)(3)(azine)(2) Complexes. Competitive Reductions of 4-Nitrobenzoate and Azine in Thermally and Photochemically Induced Redox Processes.
The photochemically and thermally induced redox reactions of the (4-nitrobenzoate)Re(CO)(3) (azine) (azine = 1,10-phenanthroline, 2,2'-bipyridine, and (4-phenylpyridine)(2)) were investigated by flash photolysis and pulse radiolysis. Processes characterized as intramolecular charge transfers from coordinated azine radicals to the 4-nitrobenzoate ligand and vice versa were observed in a 1-100 &mgr;s time scale by pulse radiolysis. In photochemical experiments, the conversion among metal to ligand charge-transfer excited states, i.e., from the Re to azine to the Re to 4-nitrobenzoate charge-transfer excited state, involves intermediates with lives of picoseconds. A mechanism for the conversions that incorporates intraligand excited states is discussed.
Feliz
M.
M
Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556.
Ferraudi
G.
G