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Resumen:
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Biscyclometalated IrIII complexes involving boron-dipyrromethene (BODIPY)-based ancillary ligands, where the BODIPY unit is grafted to different chelating cores (acetylacetonate for Ir-1 and Ir-2, and bipyridine for Ir-3) by the BODIPY meso position, have been synthesized and characterized. Complexes with the BODIPY moiety directly grafted to acetylacetonate (Ir-1 and Ir-2) exhibit higher absorption coefficients (??4.46×104 m?1 cm?1 and 3.38×104 m?1 cm?1 at 517 nm and 594 nm, respectively), higher moderate fluorescence emission (?fl?0.08 and 0.22 at 528 nm and 652 nm, respectively) and, in particular, more efficient singlet oxygen generation upon visible-light irradiation (???0.86 and 0.59, respectively) than that exhibited by Ir-3 (???0.51, but only under UV light). Phosphorescence emission, nanosecond time-resolved transient absorption, and DFT calculations suggest that BODIPY-localized long-lived 3IL states are populated for Ir-1 and Ir-2. In vitro photodynamic therapy (PDT) activity studied for Ir-1 and Ir-2 in HeLa cells shows that such complexes are efficiently internalized into the cells, exhibiting low dark- and high photocytoxicity, even at significantly low complex concentration, making them potentially suitable as theranostic agents. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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