770727-75-8Relevant academic research and scientific papers
Increasing the triplet lifetime and extending the ground-state absorption of biscyclometalated Ir(III) complexes for reverse saturable absorption and photodynamic therapy applications
Wang, Chengzhe,Lystrom, Levi,Yin, Huimin,Hetu, Marc,Kilina, Svetlana,McFarland, Sherri A.,Sun, Wenfang
, p. 16366 - 16378 (2016/10/31)
The synthesis, photophysics, reverse saturable absorption, and photodynamic therapeutic effect of six cationic biscyclometalated Ir(iii) complexes (1-6) with extended π-conjugation on the diimine ligand and/or the cyclometalating ligands are reported in this paper. All complexes possess ligand-localized 1π,π? absorption bands below 400 nm and charge-transfer absorption bands above 400 nm. They are all emissive in the 500-800 nm range in deoxygenated solutions at room temperature. All complexes exhibit strong and broad triplet excited-state absorption at 430-800 nm, and thus strong reverse saturable absorption for ns laser pulses at 532 nm. Complexes 1-4 are strong reverse saturable absorbers at 532 nm, while complex 6 could be a good candidate as a broadband reverse saturable absorber at 500-850 nm. The degree of π-conjugation of the diimine ligand mainly influences the 1π,π? transitions in their UV-vis absorption spectra, while the degree of π-conjugation of the cyclometalating ligand primarily affects the nature and energies of the lowest singlet and emitting triplet excited states. However, the lowest-energy triplet excited states for complexes 3-6 that contain the same benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine (dppn) diimine ligand but different cyclometalating ligands remain the same as the dppn ligand-localized 3π,π? state, which gives rise to the long-lived, strong excited-state absorption in the visible to the near-IR region. All of the complexes exhibit a photodynamic therapeutic effect upon visible or red light activation, with complex 6 possessing the largest phototherapeutic index reported to date (>400) for an Ir(iii) complex. Interactions with biological targets such as DNA suggest that a novel mechanism of action may be at play for the photosensitizing effect. These Ir(iii) complexes also produce strong intracellular luminescence that highlights their potential as theranostic agents.
Novel orange-red light-emitting polymers with cyclometaled iridium complex grafted in alkyl chain
Ying, Lei,Zou, Jianhua,Zhang, Anqi,Chen, Bing,Yang, Wei,Cao, Yong
, p. 2727 - 2734 (2009/12/06)
Novel poly(fluorene-alt-carbazole) (PFCz) based copolymers with 3,6-carbazole-N-alkyl grafted iridium complex using 2,3-diphenylpyrazine as ligand (IrBpz) were synthesized by Suzuki polycondensation. The emission of host polymer, PFCz, was completely quen
