Iridium polypyridine complexes cyclometallated, luminescent

Iridium complexes have recently been investigated as luminescent sensors able to monitor the variation of homocysteine and cysteine levels in cells (of significance to the physiological balance in biology), in this case using a cationic iridium(III) complex. Furthermore, zinc ion sensing in vitro was possible via a family of cyclometallated iridium(III) polypyridine compounds including a di-2-picolylamine. ... 

Luminescent cyclometallated iridium(III) polypyridine biotin complexes [Ir(NAC)2(bpy-CH2-NH-C2-NH-biotin)]+ (NAC = ppy, mppy, ppz, mppz, bzq, pq)... 

A related series of novel cyclometallated iridium(III) polypyridine thiourea complexes also display anion-induced luminescence quenching. The representative complex 89 was tested in acetonitrile solution with fluoride, acetate and dihydrogenphosphate, and gave logic values for the 1 1 complex of 3.38,... 

Luminescent organometallic complexes used for cell imaging can be divided in two main families, namely (i) carbonyl complexes, most commonly octahedral rhenium c-tricarbonyl derivatives incorporating a polypyridine ligand and (ii) cyclometalated complexes such as iridium and platinum derivatives containing the ubiquitous 2-phenylpyridine unit (complexes 1-3 in Scheme 11.2). 

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