Assembly of a Heterotrimetallic Zn2Dy2Ir Pentanuclear Complex toward Multifunctional Molecular Materials

Rational selection of metal ions and organic ligands to synthesize metal-organic complexes (MOCs) is necessary for constructing multifunctional materials. Herein, we have obtained a novel heterotrimetallic Zn₂Dy₂Ir pentanuclear MOC by the assembly of Dy^III, luminescent Zn^II(valpn), and [Ir^III(H₂L)(ppy)₂]Cl metalloligands (Hppy = 2-phenylpyridine, H₂L = 2,2'-bipyridine-5,5'-di-p-benzoic acid). Single-crystal structural analysis shows that the central [Ir^III(L)(ppy)₂]^- bridges two ZnDy moieties using two carboxylates of L^2-. Measurements of organic light-emitting diodes (OLEDs) show that the maximum luminance is 284.2 cd/m² and the turn-on voltage is 6 V. Magnetic studies reveal that Zn₂Dy₂Ir is a field-induced single-molecule magnet (SMM) with an energy barrier of 19.1(2) K under a 2 kOe dc field. Zn₂Dy₂Ir shows luminescence sensing with a quenching efficiency of up to 99.0% for 2,4,6-trinitrophenol (TNP).