The deuterated tris(hexafluoroacetylacetonato)neodymium(III) complex, Nd(HFA-D) 3 , was obtained by ketoenol tautomerism reaction of Nd(HFA) 3 in methanol-d 4 . The emission of Nd(HFA-D) 3 was observed in the following anhydrous deuterated organic solvents: methanol-d 4 , acetone-d 6 , THF-d 8 , DMF-d 7 , and DMSO-d 6 .The intensity and lifetime of the emission in DMSO-d 6 are much superior to those in other deuterated solvents. The specific interaction of DMSO molecules with Nd(HFA) 3 was confirmed by 13 C NMR and 19 F NMR analysis. The strong coordination ability of DMSO to Nd 3+ ion in Nd(HFA-D) 3 led to the enhanced emission in DMSO owing to the suppression of radiationless transition via vibrational excitation of D 2 O molecules in the vicinity of Nd(HFA-D) 3 .