Encapsulation of cationic iridium(iii) tetrazole complexes into a silica matrix : synthesis, characterization and optical properties
Zanoni, Ilaria (National Research Council of Italy. Institute of Science and Technology for Ceramics)
Fiorini, Valentina (University of Bologna. Department of Industrial Chemistry Toso Montanari)
Rosado, Marcos (Institut Català de Nanociència i Nanotecnologia)
Ballesteros, Belén (Institut Català de Nanociència i Nanotecnologia)
Androulidaki, Maria (IESL-FORTH)
Blosi, Magda (National Research Council of Italy. Institute of Science and Technology for Ceramics)
Ortelli, Simona (National Research Council of Italy. Institute of Science and Technology for Ceramics)
Stagni, Stefano (University of Bologna. Department of Industrial Chemistry Toso Montanari)
Dondi, Michele (National Research Council of Italy. Institute of Science and Technology for Ceramics)
Costa, Anna Luisa (National Research Council of Italy. Institute of Science and Technology for Ceramics)

Date:	2018
Abstract:	Herein we report the easy incorporation of brightly phosphorescent cationic iridium(iii) tetrazole complexes into a silica based matrix via an easily scalable colloidal process. For this purpose, two cationic Ir(iii) emitters bearing 5-aryl tetrazole ligands (R-CN) were selected: blue [FIrPTZ-Me] (C^N = Fppy; N^N = PTZ-Me-2-(2-methyl-2H-tetrazol-5-yl)pyridine) and red [IrQTZ-Me] (C^N = ppy; N^N = QTZ-Me-2-(2-methyl-2H-tetrazol-5-yl)quinoline). The cationic complexes were readily adsorbed to negatively charged silica nanoparticles and trapped in the sol-gel matrix. The sol-to-solid phase transfer was performed by using an innovative spray-freeze-drying technique, leading to the formation of phosphorescent solid micro-granules. The structural and optical characterisation of the Ir(iii) complexes together with SiO nanoparticles, nanosols (Ir@SiO) and powders (Ir@SiO powders), revealed how the presence of the Ir(iii)-based complexes did not alter the morphology of the colloidal silica or granulated phases. Moreover, the silica matrix did not interfere with the optical properties of the embedded complexes. The distribution of [FIrPTZ-Me] and [IrQTZ-Me] in the spray-freeze-dried powders was qualitatively evaluated by fluorescence microscopy, revealing how the luminescent particles were homogeneously dispersed all over the silica matrix. Interestingly, in aqueous solution the release of complex [FIrPTZ-Me] from the corresponding Ir@SiO powder is almost negligible, therefore suggesting that a strong interaction occurs between the host-silica matrix and the Ir(iii) guest complex.
Grants:	European Commission 654360 Ministerio de Economía y Competitividad SEV-2013-0295
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Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	New journal of chemistry, Vol. 42, Issue 12 (June 2018) , p. 9635-9644, ISSN 1369-9261

DOI: 10.1039/c8nj01514g

Postprint 21 p, 1.6 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles