Luminescent Study on Nd 3+ Complexes Containing Carboxylate‐Dithiolene and Alkoxide‐Dithiolene Ligands

Reaction of ligand L H 2 (4,5‐bis[carboxymethylthio]‐1,3‐dithiol‐2‐thione) with neodymium silyl‐amide (Nd[N(TMS) 2 ] 3 ; TMS= ‐SiMe 3 ), in a ratio 2:1, yields a neodymium‐dithiolene‐carboxylato complex ( 1 ) (Nd( L H) L ). Similarly, reaction of 2 equivalents of L′ H 2 (4,5‐bis[2′‐hydroxyethyl)thio]‐1,3‐dithiol‐2‐thione) and one equivalent of neodymium silyl‐amide (Nd[N(TMS) 2 ] 3 ) allowed the isolation of complex 2 , with a ligand:metal ratio of 3:2. ATR‐IR spectrum of 1 displays a broad band characteristic of an OH group showing that one carboxylate group remains protonated. Emission spectrum of complex 1 under excitation in the visible region (at 360 nm i.e . on the ligand) displayed typical emission bands of the Nd 3+ , showing that energy transfer from the ligand to the lanthanide was achieved ( i.e. “antenna effect”). No significant quenching from the remaining –OH group was detected. In the case of complex 2 , the main emission bands characteristic of the Nd 3+ ion have been observed, by excitation at 495 nm.