Acetylacetonate BODIPY-Biscyclometalated Iridium(III) Complexes: Effective Strategy towards Smarter Fluorescent Photosensitizer Agents

作者：Palao Eduardo; Sola Llano Rebeca; Tabero Andrea; Manzano Hegoi; Agarrabeitia Antonia R; Villanueva Angeles; Lopez Arbeloa Inigo; Martinez Martinez Virginia^*; Ortiz Maria J^*

来源：Chemistry - A European Journal, 2017, 23(42): 10139-10147.

DOI：10.1002/chem.201701347

• BODIPY
• fluorescent probes
• iridium(III) complexes
• photodynamic therapy
• singlet oxygen

Biscyclometalated Ir-III 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 (E approximate to 4.46x10(4)m(-1)cm(-1) and 3.38x10(4)m(-1)cm(-1) at 517nm and 594nm, respectively), higher moderate fluorescence emission (phi(fl)approximate to 0.08 and 0.22 at 528nm and 652nm, respectively) and, in particular, more efficient singlet oxygen generation upon visible-light irradiation (phi approximate to 0.86 and 0.59, respectively) than that exhibited by Ir-3 (phi approximate to 0.51, but only under UV light). Phosphorescence emission, nanosecond time-resolved transient absorption, and DFT calculations suggest that BODIPY-localized long-lived (IL)-I-3 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.

• 出版日期2017-7-26