Intramolecular energy transfer in ytterbium organic chelates

Abstract

The 2F52 → 2F72 intra-multiplet transition has been observed as a luminescence emission in the tris-dibenzoylmethane-Yb+++ chelate. A single strong luminescence line was recorded at 9710 ± 40 A upon excitation of the broad π, π∗ absorption band of the chelate with 3650 A light. The transition frequency agrees well with earlier observations on the unique intra-multiplet transition of Yb+++. The intramolecular energy transfer is unusual in that the apparent electronic energy difference between the initial and final states is over 10000 cm−1. The importance of vibrational interaction in the mechanism of energy transfer is pointed out.