Cyclometalated Ir(III) Complexes with Curcuminoid Ligands as Active Second-Order NLO Chromophores and Building Blocks for SHG Polymeric Films

• Published in: Inorganics Vol. 8; no. 5; p. 36
• Main Authors: Fontani, Mattia, Colombo, Alessia, Dragonetti, Claudia, Righetto, Stefania, Roberto, Dominique, Marinotto, Daniele
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-05-2020
• Subjects: cyclometalated iridium(III) complexes; EFISH; second-harmonic generation; second-order nonlinear optics
• ISSN: 2304-6740; 2304-6740
• DOI: 10.3390/inorganics8050036

The second-order nonlinear optical (NLO) properties of iridium(III) complexes having two cyclometalated 2-phenylpyridines and curcumin or tetrahydrocurcumin as ancillary ligand have been investigated both in solution and as guest in a polymeric organic matrix. In solution, these complexes are characterized by a significant second-order NLO response, as determined by the Electric Field Induced Second Harmonic (EFISH) technique, like the related complex with acetylacetonate. Whereas the low second-harmonic generation response of a composite film of [Ir(2-phenylpyridine)2(acetylacetonate)] in polymethyl methacrylate was not stable and fell down to zero upon turning off the electric field. A good and stable response was obtained with a film based on the iridium(III) complex bearing two cyclometalated 2-phenylpyridines and curcumin.