Sensitized luminescence from phenanthridine appended lanthanide complexes: analysis of triplet mediated energy transfer processes in terbium, europium and neodymium complexes.

Time resolved luminescence spectroscopy and laser flash photolysis were used to probe the energy transfer processes in the Eu, Nd and Tb complexes of N-(2-phenanthridinylmethyl)-N',N'',N'''-tris[(1R)-1-phenylethyl]-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetamide. The ligand, chosen because of the high kinetic stability of lanthanide complexes derived from amide-functionalized azamacrocycles, bears a phenanthridine chromophore that absorbs light at 355 nm, and which can be protonated at low pH. Triplet mediated energy transfer to the metal center occurs in the protonated complexes. [on SciFinder (R)]