Efficient blue light emitting materials based on m-carborane–anthracene dyads. Structure, photophysics and bioimaging studies

Efficient monosubstitution of the non-iodinated, mono-iodinated and di-iodinated m-carborane cluster at one Ccluster has led to the preparation of three single organic molecule-carborane dyads (4–6), which exhibited exceptional fluorescence properties with quantum yield values of 100% in solution, f...

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Detalles Bibliográficos
Autores: Chaari, Mahdi, Kelemen, Zsolt, Choquesillo-Lazarte, Duane, Gaztelumendi, Nerea, Teixidor, Francesc, Viñas, Clara, Nogués, Carme, Núñez Aguilera, Rosario
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/197954
Acceso en línea:http://hdl.handle.net/10261/197954
Access Level:acceso abierto
Palabra clave:Aggregation-induced emission
Solid-state emission
Charge-transfer
Excimer formation
Boron clusters
O-carboranes
Photoluminescence
Flourescence
Descripción
Sumario:Efficient monosubstitution of the non-iodinated, mono-iodinated and di-iodinated m-carborane cluster at one Ccluster has led to the preparation of three single organic molecule-carborane dyads (4–6), which exhibited exceptional fluorescence properties with quantum yield values of 100% in solution, for all of them, with maxima around 415 nm, which correspond to the locally excited state (LE) emission. These results suggest that simply linking the m-carborane fragment to one anthracene unit through a CH2 spacer produces a significant enhancement of the fluorescence in the final fluorophore, probably due to the free rotation of the anthracene linked to the Ccluster. Besides, the presence of one or two iodine atoms linked to boron atoms does not cause any influence on the photophysical properties of the dyads, as it is confirmed by TD-DFT calculations. Notably, the three conjugates show good fluorescence efficiency in the aggregate state with quantum yields in the range of 19–23%, which could be ascribed to the presence of CH2, particularly for 4, and the iodine atoms in 5 and 6, which prevent π–π stacking. All these results indicate that our dyads are extremely good emitters in solution while maintaining the emission properties in the aggregate state. Crystal packing, fingerprint plot analysis, and TD-DFT calculations for the three compounds support these results. Confocal microscopy studies show that 6 is the best-internalized compound by HeLa cells via endocytosis, although 4 and 5 also presented a high fluorescence intensity emission. Moreover, due to the blue emission, this compound is an excellent candidate to be applied as a fluorescent dye in bioimaging studies.