A Window into the Workings of anti-B18H22 Luminescence-Blue-Fluorescent Isomeric Pair 3,3'-Cl-2-B18H20 and 3,4'-Cl-2-B18H20 (and Others)

0573209 - ÚACH 2024 RIV CH eng J - Journal Article
Ehn, Marcel - Bavol, Dmytro - Bould, Jonathan - Strnad, Vojtěch - Litecká, Miroslava - Lang, Kamil - Kirakci, Kaplan - Clegg, W. - Waddell, P. G. - Londesborough, Michael Geoffrey Stephen
A Window into the Workings of anti-B18H22 Luminescence-Blue-Fluorescent Isomeric Pair 3,3'-Cl-2-B18H20 and 3,4'-Cl-2-B18H20 (and Others).
Molecules. Roč. 28, č. 11 (2023), č. článku 4505. E-ISSN 1420-3049
R&D Projects: GA ČR(CZ) GA23-07563S; GA MŠMT(CZ) LM2018124
Institutional support: RVO:61388980
Keywords : anti-B18H22 * chlorination * cluster boron hydrides * excited-state lifetime * fluorescence * halogenation * luminescence * quantum yield * substitution
OECD category: Inorganic and nuclear chemistry
Impact factor: 4.6, year: 2022
Method of publishing: Open access

The action of AlCl3 on room-temperature tetrachloromethane solutions of anti-B18H22 (1) results in a mixture of fluorescent isomers, 3,3′-Cl2-B18H20 (2) and 3,4′-Cl2-B18H20 (3), together isolated in a 76% yield. Compounds 2 and 3 are capable of the stable emission of blue light under UV-excitation. In addition, small amounts of other dichlorinated isomers, 4,4′-Cl2-B18H20 (4), 3,1′-Cl2-B18H20 (5), and 7,3′-Cl2-B18H20 (6) were isolated, along with blue-fluorescent monochlorinated derivatives, 3-Cl-B18H21 (7) and 4-Cl-B18H21 (8), and trichlorinated species 3,4,3′-Cl3-B18H19 (9) and 3,4,4′-Cl3-B18H19 (10). The molecular structures of these new chlorinated derivatives of octadecaborane are delineated, and the photophysics of some of these species are discussed in the context of the influence that chlorination bears on the luminescence of anti-B18H22. In particular, this study produces important information on the effect that the cluster position of these substitutions has on luminescence quantum yields and excited-state lifetimes.
Permanent Link: https://hdl.handle.net/11104/0343661