Tunable Excimer Circularly Polarized Luminescence in Isohexide Derivatives from Renewable Resources

Abstract

Organic compounds showing circularly polarized luminescence (CPL) are at the forefront of novel applications and technologies. Here we show the synthesis and chiroptical properties of pyrene and perylene derivatives of inexpensive chiral scaffolds: isomannide and isosorbide. Low‐intensity ECD spectra were obtained, suggesting the absence of chromophore interaction in the ground state, except in the case of isomannide bis‐perylenecarboxylate, whose ECD spectrum showed a positive exciton couplet. All isomannide derivatives, with the only exception of the one containing a pyrenecarboxylate and a perylenecarboxylate, exhibited excimer CPL spectra, whereas isosorbide derivatives did not show any CPL. Isomannide derivatives bearing two pyrenecarboxylate or two pyrenylacetate groups showed positive CPL emission with dissymmetry factors up to 10−2, which depends on the conformational freedom of the appended units. The CPL sign, Stokes shift and order of magnitude of dissymmetry factor were reproduced by excited‐state calculations on a representative compound. Interestingly, the mixed derivative containing pyrenic units with different spacing from the isomannide scaffold showed an oppositely signed excimer band with respect to the homo‐substituted derivatives.

Chiral Anthranyl Trifluoromethyl Alcohols: Structures, Oxidative Dearomatization and Chiroptical Properties

“…The access to tunable chiroptical properties is highly desirable to broaden the scope of applications, especially in the fields of detection and materials [43] . Classically, this is achieved by synthetizing a series of different structures [23c,24,44] . Recently, several switchable compounds were designed and offered in‐situ tunable and reversible chiroptical properties thanks to an external stimulus (light, pH, redox or molecular inputs).…”

Short-process synthetic strategies of sustainable isohexide-based polyesters towards higher molecular weight and commercial applicability

“…polyester imides) and formation of the Grandjean texture. 54,57 Thus far, isohexides have been mostly explored for polyester synthesis, given that polyesters are one of the most important polymeric materials for industrial applications (PET, the largest polyester species, has an annual production capacity exceeding 26 million tons globally nowadays 58 ). The publications of isohexide-based polyesters account for 47.7% of the total isohexide-based polymers (Fig.…”

Renewable Resources for Enantiodiscrimination: Chiral Solvating Agents for NMR Spectroscopy from Isomannide and Isosorbide

“…However, the interaction of two appended moieties was even observed in some isosorbide derivatives, due to their particular spatial arrangement. 31 …”

“…Indeed, through a simple derivatization of the two hydroxyl groups, the characteristic chiral cavity of their scaffold (Figure ) can be functionalized, thus leading to new compounds, whose properties depend not only on the nature of the introduced moieties but also on the different stereochemistry of the native hydroxyl groups. Due to these characteristics, isohexides were successfully employed as starting materials in the preparation of chiral ligands, organocatalysts, and chiral ionic liquids. , In particular, starting from isomannide, bidentate ligands ,− and ionic molecular tweezers , were obtained by virtue of the endo arrangement of the hydroxyl groups, which allows the appended units to be sufficiently close to each other. However, the interaction of two appended moieties was even observed in some isosorbide derivatives, due to their particular spatial arrangement …”

“…Due to these characteristics, isohexides were successfully employed as starting materials in the preparation of chiral ligands, organocatalysts, and chiral ionic liquids. , In particular, starting from isomannide, bidentate ligands ,− and ionic molecular tweezers , were obtained by virtue of the endo arrangement of the hydroxyl groups, which allows the appended units to be sufficiently close to each other. However, the interaction of two appended moieties was even observed in some isosorbide derivatives, due to their particular spatial arrangement …”