Excimer‐Based On‐Off Bis(pyreneamide) Macrocyclic Chemosensors

Abstract

A series of bis(pyreneamide) macrocycles, synthesized in two steps from THF, THP, oxepane and 1,4-dioxane, are tested as chemosensors for a large range of mono-, di-and trivalent cations. In their native states, these macrocycles exhibit a strong excimer fluorescence that is quenched upon the addition of the metal ions (alkaline, alkaline earth, p-, d-, and f-block metals). UV-Vis spectrophotometric titrations, cyclic voltammetry, excimer fluorescence quenching, and transient absorption spectroscopy experiments helped characterize the On-Off changes occurring upon binding and demonstrate that the highest stability constants are obtained with divalent cations Ca 2+ and Ba 2+ specifically.

From reactive carbenes to chiral polyether macrocycles in two steps – synthesis and applications made easy?

“…Using polyether macrocycles 1d, a systematic analysis of the binding properties of a large range of mono-, di-and trivalent cations (alkaline, alkaline earth, p-, d-, and f-block metals) was performed by means of UV-Vis spectrophotometric titrations, cyclic voltammetry, excimer uorescence quenching and transient absorption spectroscopy experiments. 31 This study demonstrated that the best binding constants and most efficient quenching of EF are obtained with divalent cations (Ba 2+ and Ca 2+ specically) in acetonitrile, while monovalent cations (Na + and K + specically) afford similar results in CH 2 Cl 2 . 23 Interestingly, the EF properties could also be used for the direct sensing of cations in competitive aqueous media.…”

“…9). 23,31 It was observed that the uorescence of 1 can be quenched by addition of a metal ion. It was proposed that the amide C]O bonds turn inwards in the presence of such cations Fig.…”

Stereoselective deconjugation of macrocyclic α,β-unsaturated esters by sequential amidation and olefin transposition: application to enantioselective phase-transfer catalysis

“…This reaction tolerates a large variety of aromatic amines. [4][5][6][7][8]11 However, despite major efforts by the group, it was never possible to achieve the analogous 1 → 3 transformation with aliphatic amines instead of anilines. Of the two consecutive steps, it was clearly the first one that was problematic under the previous conditions.…”

Circularly‐Polarized Electrochemiluminescence from a Chiral Bispyrene Organic Macrocycle

“…Thec ompound pyrene-18C6 can be obtained in ac ombined 43 %y ield from 1,4-dioxane as ar acemate (Scheme 1). [10][11][12] Thes trong excimer is formed intramolecularly due to the unique molecular geometry,which brings the two pyrene moieties in close spatial proximity.Moreover,the chiral elements of the macrocyclic ring induce ad efined configuration of the skewed arrangement of the two pyrene units,r esulting in highly CP-PL ( Figure S1). [11] Pyrene-18C6 shows aP Lprofile dominated by as trong excimer band around 490 nm as well as ag ood photoluminescence quantum yield (24 %i nC H 3 CN,r elative to anthracene).…”

“…[11] Pyrene-18C6 shows aP Lprofile dominated by as trong excimer band around 490 nm as well as ag ood photoluminescence quantum yield (24 %i nC H 3 CN,r elative to anthracene). [10][11][12] Thes trong excimer is formed intramolecularly due to the unique molecular geometry,which brings the two pyrene moieties in close spatial proximity.Moreover,the chiral elements of the macrocyclic ring induce ad efined configuration of the skewed arrangement of the two pyrene units,r esulting in highly CP-PL ( Figure S1). [11] To determine the appropriate conditions for ECL generation, the electrochemical properties of pyrene-18C6 were investigated in acetonitrile with aglassy carbon (GC) working electrode.I nf act, the stability of the electrogenerated luminophore radicals is of fundamental importance to produce astrong ECL intensity.Due to the known instability of the pyrene cation radical that results from the electrochemical oxidation, [13] we focused our study in the cathodic domain.…”