Circular dichroism and circularly polarised luminescence of bipyrenyl oligopeptides, with piperidines added in the peptide chains

Abstract

Upon combining chiral peptides (the most basic chiral source) with pyrene moieties, we found that chiral oligopeptides bearing two-pendant pyrenyl units exhibited circularly polarised luminescence (CPL) originating from intramolecular excimers at 450-490 nm in various solvents, and the sign of their CPL signals depended on the type of solvent employed. The CPL and circular dichroism signs and intensities could be tuned by the introduction of a piperidine unit into the chiral peptide chain; thus, the obtained structure could be considered a practical Lock ON-OFF system for oligopeptide luminophores.

Smart Fluorescence Materials that Are Controllable by Hydrostatic Pressure: Peptide−Pyrene Conjugates

“…All the peptide-pyrene conjugates were prepared, and the data thus obtained showed satisfactory agreement with the literatures. [52,53]…”

“…For this purpose, we focus on the chiral peptide-pyrene conjugates [52,53] (Figure 1) that exhibited unique chiroptical properties in both ground and particularly excited states under an atmospheric pressure. Herein, we demonstrate the hydrostatic pressure-controlled chiroptical as well as photophysical properties of the smart energy-related fluorescence materials.…”

Tetrachromophoric Derivatives of Dibenzoylmethanatoboron Difluoride Based on Stereoregular Cyclotetrasiloxanes: Synthesis and Properties

“…Today, an approach based on the fixation of two or more fluorophores at close distances, that allows obtaining the excimers efficiently, is widespread. For connecting fluorophores together, alkanes, − silanes, , tetrathiazole, dendrimers, , xanthenes, , oligopeptides, , aromatic diamines, aliphatic diamines, − POSS, , SiO 2 nanoparticles, , and polymers − are used. Of particular interest is the use of cyclic compounds such as calixarenes and cyclotriphosphazenes since it allows one to control the amount of fluorophores and the geometry of the molecular system.…”

Tunable Excimer Circularly Polarized Luminescence in Isohexide Derivatives from Renewable Resources

“…Such scaffolds should maintain the fluorophore units in close proximity to foster the intramolecular excimer formation and provide the stereochemically ordered arrangement necessary for efficient excimer CPL. A few examples of significant excimer CPL were obtained by using as the chiral scaffold oligopeptides [22][23][24][25][26] or nucleic acids, [27] binaphtyls and derivatives, [28][29][30][31][32][33] dioxolanes-, [34] tetrathiazole-, [35] dibenzofuran-, [36] cyclophane-, [37] and phenylene-ethynylene-based compounds, [38] quinoline oligoamide foldamers [39] and polyetherlike macrcocycles. [40] From a synthetic point of view, such chiral scaffolds should have suitable functional groups to be derivatized with the chosen emitting units.…”