Luminescent cyclometalated iridium(III) polypyridine complexes containing a thiourea moiety : Synthesis, characterization, photophysics, electrochemistry and anion-binding properties

A series of new luminescent cyclometalated iridium(III) polypyridine thiourea complexes [Ir(N-C)₂(N-N)](PF₆) [HN-C = 2-phenylpyridine (Hppy), N-N = N-ethyl-N′-1,10-phenanthrolin-5-yl thiourea (phen-TU-Et) (1a), N-phenyl-N′-1,10-phenanthrolin-5-yl thiourea (phen-TU-Ph) (1b), N-(1-adamantanemethyl)-N′-1,10-phenanthrolin-5-yl thiourea (phen-TU-MeA) (1c); HN-C = 7,8-benzoquinoline (Hbzq), N-N = phen-TU-Et (2a), phen-TU-Ph (2b), phen-TU-MeA (2c); HN-C = 2-phenylquinoline (Hpq), N-N = phen-TU-Et (3a), phen-TU-Ph (3b), phen-TU-MeA (3c)] have been synthesized and characterized. The photophysical and electrochemical properties of these complexes have been investigated. On the basis of the photophysical and electrochemical data, the nature of the emissive states has been assigned. The thiourea moieties of the complexes allow them to act as receptors for anions; the binding of OAc^-, F^-, and H₂PO ₄ ^- to the complexes has been investigated by emission titrations. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.