A time-resolved study of the mechanism of the energy transfer from a ligand to the lanthanide(III) ion in solutions and solid films

The photochemical properties of some lanthanide chelates developed for immu nohistochemistry have been studied in water and in solid Langmuir-Blodgett films. The fluorescence and tripler-state lifetimes of 4-(phenylethynyl)pyr idine (PET), di[(phenylethynyl)pyridine] (D-PET), phenylterpyridine (PTP) a nd their tetra- or penta-acid derivatives (-TA or -PA) were measured in the presence and absence of Gd(III)-, TD(III)- and Eu(III)-ions. The mechanism for the total process and the rate constants and quantum yields for the in dividual reaction steps and for the total process were determined in water solution. Time-resolved absorption and luminescence methods were also used to study the energy transfer between an amphiphilic 4-[4-[(C10H12)(2)NCO]ph enylethynyl]pyridine tetra acid (A-PET-TA) and the Tb(III)- and Eu(III)-ion s in solid Langmuir-Blodgett films. Luminescence and transient absorption r ate constants were determined. Copyright (C) 2000 John Wiley & Sons, Ltd.