Determination of intramolecular energy-transfer efficiency in ytterbium chelates

The quantum yield of²F_5/2 →²F_7/2 luminescence of the Yb³⁺ ion has been measured for ytterbium tris-thenoyltrifluoroacetonate upon excitation in the UV S₀ → S₁ absorption band of a ligand and in the IR²F_7/2 →²F_5/2 absorption band of the Yb³⁺ ion. It has been established that the quantum efficiency of intramolecular transfer of electron excitation energy from the lowest triplet state of the ligand to the excited²F_5/2 level of Yb³⁺ is equal to unity. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 539–542, July–August, 2000.