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Utility of tris(4-bromopyridyl) europium complexes as versatile intermediates in the divergent synthesis of emissive chiral probes
journal contributionposted on 2015-09-15, 13:23 authored by Stephen ButlerStephen Butler, Martina Delbianco, Nicholas H. Evans, Andrew T. Frawley, Robert Pal, David Parker, Robert S. Puckrin, Dmitry S. Yufit
The synthetic utility of europium complexes with three coordinated 4-bromopyridyl groups for chromophore elaboration has been assessed in palladium-catalysed Sonogashira coupling reactions, and in copper(I) mediated click reactions of the triazide derivative, generated in situ. The crystal structure of the Eu complex of a p-OMe-phenyl substituted triazole at 100 K is reported in which the pendant triazole sensitising moieties interdigitate in the solid-state lattice. The triazole complex can be separated into Δ and Λ enantiomers by chiral HPLC but is weakly emissive in methanol (ε 5.5 mM−1 cm−1; λexc 320 nm; ϕ 0.2%), contrasting with a set of four alkynyl–aryl derivatives which are one thousand times brighter and absorb strongly with broad absorption maxima in the range 332 to 360 nm. An enantiopure europium complex gives an intense CPL signal in solution that is the strongest yet reported.
We thank the ERC (FCC 266804), CISbio Bioassays, the Royal Society and EPSRC for support.
Published inDALTON TRANSACTIONS
Pages5721 - 5730 (10)
CitationBUTLER, S.J. ... et al, 2014. Utility of tris(4-bromopyridyl) europium complexes as versatile intermediates in the divergent synthesis of emissive chiral probes. Dalton Transactions, 43 (15), pp. 5721 - 5730.
Publisher© The Royal Society of Chemistry
- AM (Accepted Manuscript)
Publisher statementThis work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
NotesThis is the accepted version of an article subsequently published in the journal, Dalton Transactions [© The Royal Society of Chemistry]. The definitive version is available at: http://dx.doi.org/10.1039/c4dt00253a.