Self-sorting chiral organogels from a long chain carbamate of 1-benzyl-pyrrolidine-3,4-diol

Abstract

(3S, 4S)-1-benzylpyrrolidine-3,4-diyl bis(dodecylcarbamate), a pyrrolidine ring bearing two long carbon chains connected by carbamate functionalities, is the origin of stable gels in both polar and apolar solvents. Several experimental and theoretical techniques (cryo-TEM, AFM, DSC, circular dichroism (CD), molecular mechanics calculations and CD simulations) were used to describe the formation and the characteristics of the chiral supramolecular structures and fibers constituting the gel. The chirality at both supramolecular and microscopic level depends on the configuration of the stereogenic centers of the pyrrolidine unit. The gels formed by the two enantiomers of the gelator and their mixtures display enantiomeric discrimination resulting in a self-sorting process. In fact, separate fibers of opposite helicity are obtained, which suggests this class of compounds has strong potential for realizing functionalized chiral architectures

A supramolecular gel based on a glycosylated amino acid derivative with the properties of gel to crystal transition

“…1,2 With the development of advanced soft nanomaterials over the past few years, there has been growing interest in the design and synthesis of LMWGs from a wide spectrum of organic molecules [3][4][5][6] , such as cholesterols, 7 carbamates, 8 carbazoles, 9, 10 amino acids [11][12][13] and carbohydrate derivatives 14,15 for the application in chemical sensors, drug delivery, enzyme immobilization and solar cells. 1,2 With the development of advanced soft nanomaterials over the past few years, there has been growing interest in the design and synthesis of LMWGs from a wide spectrum of organic molecules [3][4][5][6] , such as cholesterols, 7 carbamates, 8 carbazoles, 9, 10 amino acids [11][12][13] and carbohydrate derivatives 14,15 for the application in chemical sensors, drug delivery, enzyme immobilization and solar cells.…”

Surface wet-ability modification of thin PECVD silicon nitride layers by 40 keV argon ion treatments

“…The surface morphology of the investigated samples was tested by an atomic force microscope model Unisolver P47 from NT-MDT (Cicchi et al, 2010). Analyses were performed in semi-contact mode with a silicon tip with a nominal radius of less than 10 nm.…”

Techniques for the Characterisation of Molecular Gels

“…[115][116][117] Chirality at the nanoscale level can sometimes be observed by electron microscopy, 38 but there are many cases in which chiral molecules do not assemble into morphologies that are visibly chiral. Given the limitations associated with sample drying, microscopy methods are not always the most representative way of studying what is truly present within the gel-phase.…”

“…In spite of these limitations, however, it is possible to achieve useful information about morphology from AFM, 19 including the ability to observe helical fibres, with the chirality being translated from the molecular scale to the nanoscale (Figure 2.10). [56][57][58] In a key paper, AFM was used not only to determine that gel fibres had formed from a TTF-derivative, but also to demonstrate they were conductive ''wire-like'' objects after doping by exposure to iodine vapour. 59,60 This was achieved by using current-sensing (conductive) AFM on a graphite surface.…”