Optimization of Aqueous Stability versus π‐Conjugation in Tetracationic Bis(triarylborane) Chromophores: Applications in Live‐Cell Fluorescence Imaging. Issue 32 (30th April 2019)

• Record Type: Journal Article
• Authors: Griesbeck, Stefanie; Ferger, Matthias; Czernetzi, Corinna; Wang, Chenguang; Bertermann, Rüdiger; Friedrich, Alexandra; Haehnel, Martin; Sieh, Daniel; Taki, Masayasu; Yamaguchi, Shigehiro; Marder, Todd B.
• Is Part Of: Chemistry. Volume 25:Issue 32(2019)
• Page Start: 7679
• Page End: 7688
• Publication Date: 2019-04-30
• Subjects: boranes -- boron -- fluorescence -- imaging -- luminescence; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201900723
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The stability of tetracationic triarylboranes in dilute aqueous solution was investigated by tuning the steric demand of the linker in a ( para ‐( N, N, N ‐trimethylammonio)xylyl)2 B–(linker)–B( para ‐( N, N, N ‐trimethylammonio)xylyl)2 structure. With increasing steric bulk of the linker, namely 1, 4‐phenylene, 2, 2′′′‐(3, 3′′′‐dimethyl)‐5, 2′:5′, 2′′:5′′, 5′′′‐quaterthiophene, 9, 10‐anthracenylene, and 4, 4′′′‐(5′‐(3, 5‐dimethylphenyl))(5′′‐(3′′′, 5′′′‐dimethylphenyl))‐2′, 2′′‐bithiophene, the stability of the compounds increased. The anthracene‐based chromophore, compound 3M is water‐stable for at least 48 h, is nontoxic to cells and exhibits an exceedingly high fluorescence quantum yield of 0.86 in water making it an ideal candidate for confocal live‐cell imaging of lysosomes. Abstract : Anthracene as bulky linker : Changing the steric demand of the linker between two dicationic BAr2 groups, leads to water‐soluble and water‐stable quadrupolar tetracationic cell‐imaging agents. With anthracene as the linker, stability as well as π‐conjugation between the two boron π‐acceptors was achieved, resulting in a very high fluorescence quantum yield in water (0.86). Furthermore, its use as a lysosomal imaging agent was demonstrated.