Effect of Iodination on the Photophysics of the Laser Borane anti-B18H22: Generation of Efficient Photosensitizers of Oxygen

0507933 - ÚACH 2020 RIV US eng J - Journal Article
Londesborough, Michael Geoffrey Stephen - Dolanský, Jiří - Bould, Jonathan - Braborec, Jakub - Kirakci, Kaplan - Lang, Kamil - Císařová, I. - Kubát, Pavel - Roca-Sanjuan, D. - Frances-Monerris, A. - Slušná, L. - Noskovičová, E. - Lorenc, D.
Effect of Iodination on the Photophysics of the Laser Borane anti-B18H22: Generation of Efficient Photosensitizers of Oxygen.
Inorganic Chemistry. Roč. 58, č. 15 (2019), s. 10248-10259. ISSN 0020-1669. E-ISSN 1520-510X
R&D Projects: GA ČR(CZ) GA18-20286S
Grant - others:AV ČR(CZ) StrategieAV21/10
Program: StrategieAV
Institutional support: RVO:61388980 ; RVO:61388955
Keywords : quantum-chemical calculations * photodynamic therapy * carborane * dyads * photoluminescence
OECD category: Inorganic and nuclear chemistry; Physical chemistry (UFCH-W)
Impact factor: 4.825, year: 2019
Method of publishing: Limited access
https://pubs.acs.org/doi/10.1021/acs.inorgchem.9b01358

Treatment of the laser borane anti-B18H22 (compound 1) with iodine in ethanol gives the monoiodinated derivative 7-I-anti-B18H21 (compound 2) in 67% yield, or, by reaction with iodine or ICl in the presence of AlCl3 in dichloromethane, the diiodinated derivative 4,4′-I2-anti-B18H20 (compound 3) in 85% yield. On excitation with 360 nm light, both compounds 2 and 3 give strong green phosphorescent emissions (λmax = 525 nm, φL = 0.41 and λmax = 545 nm, φL = 0.71 respectively) that are quenched by dioxygen to produce O2(1Δg) singlet oxygen with quantum yields of φΔ = 0.52 and 0.36 respectively. Similarly strong emissions can be stimulated via the nonlinear process of two-photon absorption when exciting with 720 or 800 nm light. The high quantum yields of singlet-oxygen production, coupled with the option of two-photon excitation, make compounds 2 and 3 promising O2(1Δg) photosensitizers. The molecular structures of compounds 2 and 3 were determined by single-crystal X-ray crystallographic studies as well as multinuclear NMR spectroscopy and mass spectrometry. Time-resolved UV-vis spectroscopy was used to delineate their photophysical properties, and the electronic-structure properties of the emitting species were determined by means of multiconfigurational quantum-chemistry computations.
Permanent Link: http://hdl.handle.net/11104/0298896


Research data: ACS publications, CCDC