Iridium Heteroleptic Cyclometalated Complexes: Applications and
Perspectives
Carlo Nervi, Roberto Gobetto, Claudio Garino, Giorgio Volpi, Anita Toscani
University of Turin, Department of Chemistry, via P. Giuria 7, 10125, Torino, Italy, e-mail: carlo.nervi@unito.it
Interest in iridium(III) cyclometalated complexes is continuously renewed due to their excellent and tuneable photophysical properties (i.e. high emission quantum yields, long lifetimes, high thermal- and photo-stabilities). Application fields of these versatile complexes span from efficient light generation in Organic Light Emitting Diodes, Active-Matrix OLED, and Light Electrochemical Cells, to photosensitizers for singlet oxygen production in photodynamic therapies and for effective artificial photosynthesis in light-harvesting technologies.
We synthesized and characterized several heteroleptic cyclometalated Ir complexes and rationalized their photophysical properties by means of DFT and TDDFT calculations [1]. The complex [Ir(ppy)2(2,2’-dipyridylketone)]+ (ppy =
2-phenylpyridine) practically is not emissive but, as predicted [1a], the replacement of C=O by a non electroreducible conjugated group leaded to complexes having high quantum yields. New Ir complexes pinched by a N,N′ six-member ring, characterized by relatively high photoemission quantum yields, have been synthesized starting from [Ir(ppy)2
(2,2′-dipyridylketone)]+. At the same time we synthesized new
complexes and explored the photophysical properties of complexes characterized again by a six-member ring, but
now located on the C,N part of the molecule. The aim of the present communication is to illustrate the synthetic attempts in trying to get new luminescent Ir derivatives suitable for photo applications..
[1] a) C. Nervi et al., Chem. Eur. J. 15 (2009) 6415, b) Cat.Today 158 (2010) 22, c) Dalton
