NEW APPROACH TO THE MEASUREMENT OF LUMINESCENCE RISE TIMES - STUDY OF THE RISE TIMES OF RHODIUM(III) COMPLEXES

A new approach to the measurement of luminescence rise times is described which eliminates the problems associated with different transit times of the photomultiplier for different wavelengths. The approach is based on a wavelength shifter with a very long lifetime. The method and a suitable wavelength shifter are described. The technique is used to study the rise times of photochemically important cis-[RhL2(XY)]+ complexes where L = 2,2′-bipyridine, 1,10-phenanthroline, or ethylenediamine and X, Y = Cl-, Br-. In the best cases, with a 10-ns excitation pulse, the method shows rise times to be ≤0.1 ns. Relaxation pathways and photochemical implications are discussed. © 1979 American Chemical Society.