Cyclometalated Ir(III) Complex as a Metalloligandand a Selective Cu(II) Sensor: Synthesis and Structural Characterizationof a Heterometallic Tetranuclear Ir(III)/Cu(II) Complex

摘要

A cyclometalated Ir(III) complex, [Ir(ppy)2(LH)] (>2) [LH2 = 1,2-bis(pyridine-2-carboxamido)benzene; ppyH = 2-phenylpyridine] was synthesized and structurally characterized. [Ir(ppy)2(LH)] contains free donor sites and functions as a metalloligand. Accordingly, it interacts with a Cu(II) salt to afford the heterometallic tetranuclear complex, [{Ir(ppy)2(L)}2{Cu2Cl2}] (>3). In the latter, a Cu2Cl2 dimer bridges the two cyclometalated Ir(III) units, resulting in a Ir^III–Cu^II–Cu^II–Ir^III motif. >2 also functions as a selective and reversible sensor for Cu²⁺, as revealed by quenching of its emission and subsequent revival of the luminescence signal upon addition of EDTA.