Iridium(III) Complexes as Broadband Reverse Saturable Absorbers and/or in vitro Theranostic Photodynamic Therapy (PDT) Reagents
讲座名称：Iridium(III) Complexes as Broadband Reverse Saturable Absorbers and/or in vitro Theranostic Photodynamic Therapy (PDT) Reagents
讲 座 人：Prof. Wenfang Sun
Iridium(III) complexes with moderate ground-state absorption in the visible to the near-IR region, long-lived triplet excited states and strong triplet excited-state absorption, and near-IR emission are promising agents for broadband reverse saturable absorption (RSA), photodynamic therapy, and bioimaging. The synthesis, photophysics, reverse saturable absorption, and in vitro photodynamic therapeutic effect and bioimaging of several series of Ir(III) complexes with extended ?-conjugation on the diimine ligand and/or the cyclometalating ligands are reported. Most of the complexes possess moderate charge-transfer absorption bands between 400 and 600 nm; and these bands are extended to 800 nm when the conjugation of the cyclometalating ligands increases. They are all emissive in the red to the NIR region in solutions at room temperature. The nature and energies of the lowest singlet and emitting triplet excited states are primarily influenced by the degree of -conjugation of the ligands. Most of the complexes can generate singlet oxygen efficiently, and exhibit a photodynamic therapeutic effect upon visible or red light activation, with one of the Ir(III) complexes possessing the largest phototherapeutic index reported to date (> 1650) for Ir(III) complexes upon white light activation. Interactions with DNA suggest that other mechanism of action may be at play for the photosensitizing effect. These complexes also produce strong intracellular luminescence that highlights their potential as theranostic PDT agents. In addition, many of the complexes exhibit strong RSA for ns laser pulses at 532 nm, and the RSA performance is influenced by the nature of the diimine and/or cyclometalating ligands.
Prof. Wenfang Sun is the James Meier Senior Professor and the Water F. and Verna Gehrts Presidential Professor at the Department of Chemistry and Biochemistry, North Dakota State University (NDSU). She has published 119 peer-reviewed journal papers and obtained over $7,000,000 research grants from NSF, etc. She also received numerious awards, including the NSF CAREER Award (2005-2011), the James A. Meier Senior Professorship (2016), the NDSU Fred Waldron Award for Outstanding Research (2012), the NDSU Walter F. and Verna Gehrts Professorship (2011), the NDSU Bison Ambassadors Apple Polisher Honoree (2009), the NDSU Featured Faculty (2006). Currently, she serves on the editorial board of five international chemistry journals. Her research program covers the organic/organometallic nonlinear optical materials, organic/organometallic light emitting materials, photosensitizers for photodynamic therapy, and optical sensing materials.