Energy transfer from a fluorescent hydrogel to a hosted fluorophore.

The fluorescent properties of a new 1,3,5-cyclohexyltricarboxamide-based low-molecular-weight hydrogelator (1) derivatized with one hydrophobic fluorophore and two hydrophilic substituents have been investigated. Gels of 1 are composed of long, nonbranched fibers of uniform diameter, as shown by cryo-transmission electron microscopy (cryo-TEM). The aggregation of the naphthalene fluorophore moieties of the gelator molecules in the gel fibers favors the occurrence of a fast energy migration process that allows a very efficient sensitization of the fluorescence of a hosted fluorophore.

Cyclohexane-based low molecular weight hydrogelators: a chirality investigation.

Seven new 1,3,5-cyclohexyltricarboxamide-phenylalanine derivatives were synthesized in order to investigate the effect of the amino acid chirality on the gelating properties of these small molecules in water. Gelation tests have shown that enantiomerically pure homochiral 1,3,5-cyclohexyltricarboxamide-L-phenylalanine is a non-hydrogelator as it crystallizes from water, whereas the heterochiral derivatives with either two L-phenylalanine moieties and one D-phenylalanine (LLD), or vice versa (DDL), are very good hydrogelators. Concentration-dependent gel-to-sol transition-temperature (T(gs)) curves for LLD or DDL gels show a sigmoidal behaviour, which is in contrast to the logarithmic curves generally observed for gels derived from low molecular weight gelators (LMWGs).

Cyclohexane bis-urea compounds for the gelation of water and aqueous solutions.

A new class of efficient hydrogelators has been developed by a simple modification of the peripheral substituents of cyclohexane bis-urea organogelators with hydrophilic hydroxy or amino functionalities. These bis-urea hydrogelators were synthesised in two or three steps using an alternative procedure to the common isocyanate method. Gelation was obtained with organic solvents, water and strongly basic aqueous solutions like 25% ammonia.

Small-angle X-ray scattering from a dual-component organogel to exhibit a charge transfer interaction.

The structure of a dual-component organogel consisting of methyl 4,6-O-(p-aminobenzylidene)-alpha-D-glucopyranoside and methyl 4,6-O-(p-nitrobenzylidene)-alpha-D-glucopyranoside in diphenyl ether was investigated with small-angle X-ray scattering (SAXS). The individual components gelatinized the solvent to yield a colorless gel and the gel fiber consisted of the crystal, providing the crystalline peaks at the same diffraction angles as those of the solid samples. When the components were mixed in equimolar ratio and dissolved in diphenyl ether, a yellow gel was formed and the crystalline peaks disappeared.

Entrapment and release of quinoline derivatives using a hydrogel of a low molecular weight gelator.

Gels of low molecular weight gelators (LMWGs) are self-assembled, thermoreversible, viscoelastic materials which can also be rendered sensitive to light, pH or chemical substances by simple chemical modifications. In addition, the ability of some of these LMWGs to gelate water (hydrogelators) makes these gels interesting, new materials for drug delivery applications. In this paper, for the first time, a release study from LMWG gels is presented.

Orthogonal self-assembly of low molecular weight hydrogelators and surfactants.

The concurrent self-assembly of new 1,3,5-trisamide-cyclohexane-based low molecular weight hydrogelators and various surfactants in water leads to the formation of self-assembled fibrillar networks with encapsulated micelles. This prototype system presents an example of orthogonal self-assembly, that is, the independent formation of two different supramolecular structures, each with their own characteristics that coexist within a single system.

Organic templates for the generation of inorganic materials.

Mankind's fascination with shapes and patterns, many examples of which come from nature, has greatly influenced areas such as art and architecture. Science too has long since been interested in the origin of shapes and structures found in nature. Whereas organic chemistry in general, and supramolecular chemistry especially, has been very successful in creating large superstructures of often stunning morphology, inorganic chemistry has lagged behind.

Charge-transfer phenomena in novel, dual-component, sugar-based organogels.

The synthesis of a new saccharide-based gelator (2) containing a donor moiety has been described. Gelation experiments of a dual-component gel consisting of a saccharide-based gelator bearing an acceptor group (1) and of 2 have been performed in a variety of organic solvents and water. Moreover, gelation tests at different molar ratios of 1 and 2 have been performed in water, octanol, and diphenyl ether.

Molecular design of "super" hydrogelators: understanding the gelation process of azobenzene-based sugar derivatives in water.

[structure: see text]. 1: R = beta-D-glucopyranoside. 2: R = alpha-D-glucopyranoside.