195. Combined reversible switching of ECD and quenching of CPL with chiral fluorescent macrocycles
     Alexandre Homberg, Elodie Brun, Francesco Zinna, Simon Pascal, Marcin Górecki, Luc Monnier, Céline Besnard, Gennaro Pescitelli, Lorenzo Di Bari, Jérôme Lacour
     Chem. Sci. 2018, 9, 7043-7052
     [ 2018 ChemSci Pick of the Week Collection & 2018 Chemical Science HOT Article Collection]

Straightforward synthesis and resolution of a series of chiral fluorescent macrocycles are presented, together with their electronic circular dichroism (ECD), strong excimer fluorescence (EF, λ 300 to 650 nm) and allied highly circularly polarized luminescence (CPL, g_lum up to 1.7×10^-2). The ECD, EF and CPL responses are strongly affected by the presence of metal ions (Na⁺, Ba²⁺) thanks to deep conformational changes. While ECD signals can be almost completely reversibly inverted upon the complexation/decomplexation of metal ions in a typical binary response, CPL signals are reversibly quenched concomitantly. The designed macrocycles display thus a remarkable combination of both +/− ECD and on/off CPL reversible switching.

DOI : 10.1039/C8SC02935K 

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