Hetero-binuclear near-infrared (NIR) luminescent Zn-Nd complexes self-assembled from the benzimidazole-based ligands.

With the compound [Zn(HL(1))(2)(Py)] (H(2)L(1)=2-(1H-benzo[d]imidazol-2-yl)-6-methoxyophenol), Py=pyridine) or [Zn(HL(2))(2)(Py)] (H(2)L(2)=2-(1H-benzo[d]imidazol-2-yl)-4-bromo-6-methoxyphenol) as the precursor, complexes [ZnLn(HL(1))(2)(Py)(NO(3))(3)] (Ln=Nd, 1; Ln=Gd, 2) or [ZnLn(HL(2))(2)(Py)(NO(3))(3)] (Ln=Nd, 3; Ln=Gd, 4) were obtained by the further reaction with Ln(NO(3))(3)·6H(2)O (Ln=Nd or Gd). The result of their photophysical properties shows that the strong and characteristic near-infrared (NIR) luminescence of Nd(3+) ions for complexes 1 and 3 with emissive lifetimes in microsecond range, has been sensitized from the excited state ((1)LC and (3)LC) of the benzimidazole-based ligands, and the involvement of heavy atoms (Br) at the ligand endows the enhanced NIR luminescent property.