Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Chemistry of Carbon Nanotubes

Aggregation-induced emission: phenomenon, mechanism and applications.

About Supramolecular Assemblies of π-Conjugated Systems

The aim of this critical review is to provide a broad but digestible overview of mechanochemical synthesis, i.e. reactions conducted by grinding solid reactants together with no or minimal solvent. Although mechanochemistry has historically been a sideline approach to synthesis it may soon move into the mainstream because it is increasingly apparent that it can be practical, and even advantageous, and because of the opportunities it provides for developing more sustainable methods. Concentrating on recent advances, this article covers industrial aspects, inorganic materials, organic synthesis, cocrystallisation, pharmaceutical aspects, metal complexes (including metal–organic frameworks), supramolecular aspects and characterization methods. The historical development, mechanistic aspects, limitations and opportunities are also discussed (314 references).

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Mechanochemistry: opportunities for new and cleaner synthesis

In recent years there has been immense interest in studying gels derived from low molecular mass gelators (supramolecular, or simply molecular gels). The motivation for this is not only to understand the fundamental aggregate structures in the gels at different length scales, but also to explore their potential for futuristic technological applications. Gels have been made sensitive to external stimuli like light and chemical entities by incorporating a spectroscopically active or a receptor unit as part of the gelator molecule. This makes them suitable for applications such as sensing and actuating. The diversity of gel structural architectures has allowed them to be utilized as templates to prepare novel inorganic superstructures for possible applications in catalysis and separation. Gels derived from liquid crystals (anisotropy gels) that can act as dynamically functional materials have been prepared, for example, for (re-writable) information recording. Supramolecular gels can be important in controlled release applications, in oil recovery, for gelling cryogenic fuels etc. They can also serve as media for a range of applications. This tutorial review highlights some of the instructive work done by various groups to develop smart and functional gels, and covers a wide spectrum of scientific interest ranging from medicine to materials science.

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Supramolecular gels: Functions and uses

Visible‐Light‐Harvesting Organogel Composed of Cholesterol‐Based Perylene Derivatives

A novel coordination gelator exhibits reversible chromatic and sol−gel phase-transition phenomena triggered by thermal and chemical stimuli.

A Coordination Gelator That Shows a Reversible Chromatic Change and Sol−Gel Phase-Transition Behavior upon Oxidative/Reductive Stimuli

Spontaneous Colorimetric Sensing of the Positional Isomers of Dihydroxynaphthalene in a 1D Organogel Matrix

To obtain insights into a correlation relationship between the structure and the aggregation mode in an organogel system, we synthesized gelators 2a−4a bearing a porphyrin moiety as a one-dimensional aggregation unit and amide groups as peripheral hydrogen-bonding sites. Gelators 3a and 3b bearing the amide groups at the 4-position of the meso-phenyl groups are classified as versatile gelators, gelating 10 and 14 solvents, respectively, among 23 solvents tested herein. In contrast, gelators 2a and 4a bearing the amide groups at the 3,5-positions and 3-position, respectively, are classified as poor gelators. Examination by spectroscopic methods (UV−vis, ATR−FTIR, XRD, etc.) revealed that in the organogel phase porphyrins in 3a adopt the H aggregation mode whereas those in 2a and 4a adopt the J aggregation mode. X-ray analysis of the single crystals established that in fact 3b features a columnar stack of porphyrin moieties that can be classified as the H-aggregate, whereas 2a results in a two-dimensional a...

Hydrogen-bond-assisted control of H versus J aggregation mode of porphyrins stacks in an organogel system

An amide-type copper porphyrin gelator having alkyldiacetylene tethers gives very transparent gel in Decalin, and the gel shows unique thixotropic behavior. One-dimensional aggregates generated in the gel act as templates for unimolecularly segregated polydiacetylene wiring upon UV irradiation on the surface. The polymerization along the aggregation goes to at least several micrometers long.

A Stable Single Piece of Unimolecularly π-Stacked Porphyrin Aggregate in a Thixotropic Low Molecular Weight Gel: A One-Dimensional Molecular Template for Polydiacetylene Wiring up to Several Tens of Micrometers in Length

Norifumi Fujita

Papers

Visible‐Light‐Harvesting Organogel Composed of Cholesterol‐Based Perylene Derivatives

A Coordination Gelator That Shows a Reversible Chromatic Change and Sol−Gel Phase-Transition Behavior upon Oxidative/Reductive Stimuli

Spontaneous Colorimetric Sensing of the Positional Isomers of Dihydroxynaphthalene in a 1D Organogel Matrix

Hydrogen-bond-assisted control of H versus J aggregation mode of porphyrins stacks in an organogel system

A Stable Single Piece of Unimolecularly π-Stacked Porphyrin Aggregate in a Thixotropic Low Molecular Weight Gel: A One-Dimensional Molecular Template for Polydiacetylene Wiring up to Several Tens of Micrometers in Length