Construction and NIR luminescent property of hetero-bimetallic Zn–Nd complexes from two chiral salen-type Schiff-base ligands

Two new near-infrared (NIR) luminescent Zn–Nd complexes [ZnL1Nd(OAc)(NO3)2] (3) and [ZnL2Nd(DMF)2(NO3)3] (4) have been obtained with two salen-type Schiff-base ligands H2L1 and H2L2, (H2L1 = N,N′-bis(3-methoxysalicylidene)-(1s, 2s)-(−)1,2-dipheneylethylenediamine and H2L2 = N,N′-bis(3-methoxysalicylidene)-(s)-2,2-diamine-1,1′-binaphthyl) from the reaction of different chiral diamines with o-vanillin. The X-ray crystal structure analysis reveals that both of them crystallize in the chiral space groups with P2(1), a = 10.1669(6), b = 19.3775(11), c = 17.4639(10) Å, β = 94.8710(10)°, V = 3428.1(3) Å3, Z = 4 for 3, and C2, a = 22.1914(13), b = 9.7886(6), c = 22.0138(13) Å, β = 118.9590(10)°, V = 4372.5(4) Å3, Z = 4 for 4. Complexes 3–4 are both dinuclear Zn–Nd structures, while suitable choice of chiral Schiff-base ligands could induce the different complexions of ligands and metal ions, and the functional control of ligand character shows a potentially effective way to the fine-tuning properties of NIR luminescence from Nd ions.