Controlling Lanthanide Exchange in Triple‐Stranded Helicates: A Way to Optimize Molecular Light‐Upconversion. (16th October 2017)

• Record Type: Journal Article
• Authors: Zare, Davood; Suffren, Yan; Nozary, Homayoun; Hauser, Andreas; Piguet, Claude
• Is Part Of: Angewandte Chemie. Volume 129:Number 46(2017)
• Page Start: 14804
• Page End: 14809
• Publication Date: 2017-10-16
• Subjects: Helikate -- Heterometallkomplexe -- Molekülbasierte Aufwärtskonversion -- Reaktionskinetik -- Reaktionsmechanismen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201709156
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The kinetic lability of hexadentate gallium‐based tripods is sufficient to ensure thermodynamic self‐assembly of luminescent heterodimetallic [GaLn(L3 )3 ] 6+ helicates on the hour time scale, where Ln is a trivalent 4f‐block cation. The inertness is, however, large enough for preserving the triple‐helical structure when [GaLn(L3 )3 ] 6+ is exposed to lanthanide exchange. The connection of a second gallium‐based tripod further slows down the exchange processes to such an extent that spectroscopically active [CrErCr(L4 )3 ] 9+ can be diluted into closed‐shell [GaYGa(L4 )3 ] 9+ matrices without metal scrambling. This feature is exploited for pushing molecular‐based energy‐transfer upconversion (ETU) at room temperature.