Enhanced Emission of Deuterated Tris(hexafluoroacetylacetonato)neodymium(III) Complex in Solution by Suppression of Radiationless Transition via Vibrational Excitation

Abstract

The deuterated tris(hexafluoroacetylacetonato)neodymium(III) complex, Nd(HFA-D)3, was obtained by keto−enol tautomerism reaction of Nd(HFA)3 in methanol-d4. The emission of Nd(HFA-D)3 was observed in the following anhydrous deuterated organic solvents: methanol-d4, acetone-d6, THF-d8, DMF-d7, and DMSO-d6. The intensity and lifetime of the emission in DMSO-d6 are much superior to those in other deuterated solvents. The specific interaction of DMSO molecules with Nd(HFA)3 was confirmed by 13C NMR and 19F NMR analysis. The strong coordination ability of DMSO to Nd3+ ion in Nd(HFA-D)3 led to the enhanced emission in DMSO owing to the suppression of radiationless transition via vibrational excitation of D2O molecules in the vicinity of Nd(HFA-D)3.