Anion-induced near-infrared (NIR) luminescent Zn2Nd and ZnNd complexes based on the pure Salen-type Schiff-base ligand

With the Zn-Schiff-base [ZnL(CH3CN)] from the pure Salen-type Schiff-base ligand H2L (H2L = N,N′-bis(salicylidene)phenylene-1,2-diamine) as the precursor, a hetero-trinuclear Zn2Nd complex [Zn2Nd(L)2(NO3)3(CH3CN)2] (1) and a hetero-binuclear ZnNd complex [ZnNd(L)2Cl(DMF)] (2) are obtained by the further reaction with Nd(NO3)3·6H2O or NdCl3·6H2O, respectively. The influence of structural differences of the two complexes on their photophysical properties shows the anionic inducement leads to the effective modulation of the NIR luminescent properties by the adjustment of the coordination sphere of the Nd3+ ions.