Constitutional Dynamic Chemistry (CDC) provides an evolutional approach to the generation of chemical diversity on both the molecular and supramolecular levels through the implementation of reversible covalent reactions and non-covalent intermolecular interactions, respectively. It confers to chemical systems a fifth dimension, that of constitution, in addition to the 4D spatial/temporal chemical space. The self-assembly of the components into well-defined architectures across size scale, controlled by mastering molecular/supramolecular constitutional affinities, embodies the flow of structural information from the molecular level toward nanoscale dimensions. It is highly dependent on the nature of the network and has been shown to be influenced by factors such as shape, valency, orientation and flexibility of components. Natural systems have built up complex evolutive functions over many centuries. The actual challenges are to implement Constitutional Dynamic Systems for confering to non-natural chemical systems the features of natural selection and functional evolution. They lie at the forefront of present cross-disciplinary research, extending over the vast field of scientific challenges related to the property (function)-driven generation of adjustable (adaptive) artificial systems and directed at understanding the fundamental aspects of the self-organization of matter, involving in particular controlled structure generation, adaptation and replication processes. They open up wide perspectives to imagining a fundamental transition from molecular/supramolecular design toward constitutional self-selection approaches, which may also bear great potential in various applications. The present special issue of the Israel Journal of Chemistry on “Constitutional Dynamic Systems” discusses, in twelve reviews and full papers, some of the most important advances in this field, focusing on various strategies for understanding and controlling such constitutional propagation of structural information. The contributions to this issue open new horizons, shortening the essential steps from molecular to functional systems. These twelve papers are structured in three groups: 1) Evolutional approaches to the generation of chemical diversity, development of the Constitutional Dynamic Libraries and their functional amplification: Benzion Fuchs and Ulrich Lüning review the use of dynamic combinatorial libraries generated via reversible covalent bonds to generate podands, macrocycles, helical architectures, etc. Some of these compounds self-generate selective transporters or specific compact architectures in the presence of the targets that induced their formation in the first time. Olof Ramström discusses one-pot synthetic strategies to prepare highly added value compounds and highlights the importance of using such concepts in organic synthesis. Mihail Stadler analyses the influence of external stimuli (pH, metal ions) on imine bond formation, shedding light on interesting experimental procedures for selective selection and modulation of small library compounds. 2) Constitutional self-assembly toward complex architectures: Virgil Percec reviews the dynamic self-assembly of dendritic systems which constitutionally lead to a remarkable collection of periodic lattices and quasi-periodic arrays which can find applications in various fields such as nano-machines and switches or porous protein mimics. Nicolas Winssinger examines the constitutional self-assembly of various target biomolecules around DNA systems. The programmability of oligonucleotide recognition offers an attractive platform for cooperative self-assembly and reactional processes of ligands that can interact with a DNA target. Damien Quemener reviews prominent self-healing polymeric systems from hard thermosets to porous nanomaterials, with the aim to highlight the potential of reversible bonds to achieve a range of such dynamic self-healing processes. 3) Constitutional Dynamic Systems- toward selective membrane and extraction systems: the contribution of Achim Müller and Mihail Barboiu discusses the functional self-assembly of porous Keplerate-type molybdenum-oxide nanocapsules embedded in surfactants. This system shows a highly selective transport of Li+ over Na+ and K+ cations through supported liquid membranes in which the nanocapsules occur in dynamic constitutional aggregates used as specific nanoscaled translocation pathways for cations. The general case of water-poor complex systems containing extractant molecules that present long-range interactions at the interface and participate to the selectivity of any multivalent ion extraction processes is discussed by Thomas Zemb's laboratory. Finally, the group of Mihail Barboiu introduces the concept of rubbery organic frameworks (ROFs), used as constitutional dynameric materials for the construction of membranes for gas separation. It provides perspectives to imagine a basic transition from macromolecular design toward constitutional approaches, which might allow achieving the molecular limit of gas permeable membranes. We hope that the findings described herein will help the readers to find answers or to imagine solutions to key questions concerning the implementation of the evolutional approaches provided by Constitutional Dynamic Chemistry towards the fascinating possibilities offered by selection, evolution, amplification, molecular recognition and replication processes. The present issue is of course not a comprehensive presentation, but a timely snapshot of the actively developing field of CDC from which the reader may gain a broader insight into the area and hopefully a source of future inspiration. 1 1 Mihail Barboiu / Jean-Marie Lehn Institut Européen des Membranes, CNRS / Université de Strasbourg Guest Editor / Guest Editor
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May 27, 2024
Zhaozheng Yang + 3
Open Access