Synthesis, structure and long-lived NIR luminescence of lanthanide ate complexes with perfluorinated 2-mercaptobenzothiazole

To obtain new efficient lanthanide-based NIR luminophores perfluorinated 2-mercaptobenzothiazole was used as a ligand. The ate-complexes [(Ln(mbt F ) 4 ) − (Na(DME) 3 ) + ] of Nd ( 1 ), Sm ( 2 ), Tb ( 3 ), Er ( 4 ), Yb ( 5 ) and [(Y(mbt F ) 4 ) − (Li(DME) 3 ) + ] ( 6 ) were synthesized in high yields by the reactions of the respective silylamide compounds Ln[N(SiMe 3 ) 2 ] 3 and M[N(SiMe 3 ) 2 ] (M = Li, Na) with 4,5,6,7-tetrafluoro-1,3-benzothiazol-2(3 H )-thione (Hmbt F ) in DME media. The complexes 1-3 and 6 were structurally characterized by X-ray diffraction analysis. It has been shown that the mbt F ligands sensitize the luminescence of Nd, Sm, Tb, Er and Yb ions upon mild UV or blue light excitation. The NIR luminescence of crystalline compounds 1 , 2 , 4 and 6 has been studied by time-resolved techniques. As expected, the compounds exhibit prolonged NIR luminescence due to the removal of C-H groups from lanthanide centers and the absence of C-O bonds in the coordination sphere of the lanthanides. The synthesized compounds are promising materials for NIR laser applications. Lanthanide ate complexes with perfluorinated 2-mercaptobenzothiazole show long-lived NIR PL in hydrogen-rich media.