Introduction
Supramolecular networks [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], cross-linked polymer networks , linked by noncovalent supramolecular interactions have attracted much interest in recent decades due to their attractive structures and interesting properties. As a kind of physical network, dynamic and reversible non-covalent bonds enable some interesting properties such as ease of processing, recyclability, stimuli response, self-healing and shape memory, which are difficult to realize with traditional polymers [12], 13]. ], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23]. So far, several non-covalent supramolecular interactions including hydrogen bonding, metal coordination, π–π stacking, hydrophobic interactions, and guest–host interactions have been introduced to create supramolecular networks [24], [25], [26 ], [27] . [28], [29], [30], [31] and offers diverse applications such as adsorption and separation, biomedical engineering, catalysis, drug delivery, etc. [19,20,[32],[33],[34] ],[ 35], [36], [37]]. However, the interconnections in common supramolecular networks are often randomly distributed and highly disordered, with no fixed direction and geometry. That is, the non-covalent interactions only act as linkers to form the physical networks, and the additional functions of the networks can only be improved by appropriate modification of the polymer backbones [38], [39], [40], [41]. ]. The introduction of geometry-specific crosslinks alters porosity, mechanical strength, processability, and solvent compatibility and offers an alternative approach to adding additional functionality to supramolecular networks [42], [43], [44]. However, since it is difficult to introduce, maintain, and characterize such interconnections in supramolecular networks, the construction of cavity–core supramolecular networks is a significant challenge.
Supramolecular Coordination Complexes (SCCs) [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56] is a class of topological structures formed by moderate and directional metallic coordination bonds. SCCs can be produced almost quantitatively by self-assembly of suitable metal ions and organic ligands [57]. So far there are a number of SCCs with different topological geometries ranging from two-dimensional metallocycles [58], [59], [60], [61], [62], [63], [64] (triangular, rectangular, rhomboidal) series and hexagons, etc.) to 3D metal cages [65], [66], [67], [68], [69], [70], [71], [72], [73], [74 ] (tetrahedron, cube, octahedron and cuboctahedron, etc.) have been described. Moderate binding energy (15–50 kcal mol−1) many metal coordination bonds provide good stability of SCCs, so they serve as host molecules for encapsulation and stabilization, separation and catalysis, etc. Efficient preparation, facial functionality, and good stability make SCCs ideal candidates as crosslinks for core-cavity supramolecular networks. Such networks can integrate the properties of SCCs and supramolecular networks, offering some unique properties and applications that are difficult to realize with traditional methods. Supramolecular networks with SCC cores offer several advantages: (1) Discrete, rigid, nanosized SCCs can act as fillers to improve the mechanical strength of polymeric materials. (2) The lattice densities of the networks can be fine-tuned by the assigned functional groups of the SCCs. (3) The internal cavity of SCCs will provide the nets with additional functions such as adsorption, separation and controlled release. (4) Dynamic metal resonance bonds endow the networks with stimulus response and self-healing properties and provide a pathway for energy dissipation to improve the mechanical compatibility of materials. (5) Fluorescence properties can be easily introduced to visualize the state of materials, and the dissociation and reconnection of metal coordination bonds can also be monitored through fluorescence changes, which is useful for understanding the relationship between mechanical mechanisms and dynamic properties of networks.
Therefore, much progress has been made in metallocycle/metallocycle supramolecular networks in recent years [42,43]. Different strategies, properties and functions have been developed in this promising field. Therefore, there is a need to write a review article summarizing the main advances in this field. In this review, we will summarize different metallocycle or metal core supramolecular networks according to the covalent or non-covalent interactions used to connect the supramolecular structures that play an important role in their applications. Let us simply summarize the integration of rigid SCCs with flexible polymer networks. Organometallic structures [75], [76], [77], [78], [79], [80], which are also considered an important class of coordination networks, are not considered in this review. In each part, the structural features, functions and applications of supramolecular networks are presented in detail. The remaining challenges and perspectives are presented at the end of this review. We hope that this Review can provide a systematic summary of the most exciting advances in supramolecular metallocycle/metal networks and inspire more and more scientists to explore this promising field.
unit excerpts
Supramolecular networks with a metallocycle core
Since the early 1990s, Fujita and Stang et al. reported a series of structurally organized metallocycles [81], [82], [83], [84], [85], [86], [87], [88], [89] with geometries ranging from richly triangular to hexagonal self-assembly of suitable metal ions and organic precursors. The geometries of metal circles are mainly determined by the shapes and angles of the structural elements. Metal coordination interactions often serve as the main drivers in metal supramolecular cycle core networks.
Supramolecular networks with a metal cage core
Through the rational design of structural elements, efficient self-assembled, structurally demanding, and sophisticated tuning-oriented metal structures containing well-defined cavities with tunable sizes and shapes can be obtained. Compared with 2D metallacycles, 3D metal cage cavities can be effectively used for guest encapsulation, which enables a variety of applications in sensing, storage, catalysis, delivery, etc. [142], [143], [144], [145]. For this reason,
Conclusions and Perspectives
This review summarizes the progress of state-of-the-art supramolecular networks of metallocycles and metal cage cores based on the non-covalent or covalent compounds used to construct these supramolecular structures. The incorporation of rigid metal structures and flexible polymer chains endows the formed networks with increased mechanical strength, tunable physical properties and diverse functions, while maintaining their dynamic properties such as self-healing and response to stimuli.
Declaration of Competing Interests
The authors declare that they are not aware of any competing financial interests or personal relationships that may appear to influence the work described in this article.
Thanks
R. Zhang DankePostdoctoral Science Foundation of China(2021M702588) and Shaanxi ProvinceNatural Science Foundation of China(2023-JC-QN-0105) for the last backup. M. Zhang is gratefully acknowledgedNational Science Foundation of China(22171219m22222112), Shaanxi Provincial Innovation Talent Promotion Plan for Science and Technology Innovation Team (2023-CX-TD-51) and Central University Basic Research Fund for financial support. F. Huang acknowledges the National Key
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© 2023 Elsevier B.V. All rights reserved.
FAQs
What are examples of supramolecular interactions? ›
Supramolecular interactions are a class of interactions categorized by their non-covalent character. Examples of supramolecular interactions include van der Waals forces, pi-pi stacking, hydrogen bonding, metal-ligand coordination, electrostatic interactions, and host-guest interactions.
What are examples of supramolecular systems? ›Colloids, liquid crystals, biomolecular condensates, micelles, liposomes and biological membranes are examples of supramolecular assemblies, and their realm of study is known as supramolecular chemistry. The dimensions of supramolecular assemblies can range from nanometers to micrometers.
What is the strength of supramolecular interactions? ›The variety and strengths of feasible supramolecular interactions is vast, ranging from strong ionic bonds with interaction strengths as high as 350 kJ mol−1 to very weak hydrogen bonds with strengths less than 5 kJ mol−1.
What is the distinction between molecular and supramolecular interactions? ›Supramolecular chemistry deals with the interactions between molecules whereas molecular chemistry deals with bonding inside the molecule.
What is supramolecular network? ›Supramolecular polymer networks consist of macromolecules interconnected by transient, noncovalent bonds such as those through hydrogen bonding, transition metal complexation, hydrophobic interaction, ionic attraction, or π–π stacking.
What are the two types of supramolecular chemistry? ›As a discipline, supramolecular chemistry may be divided into two: (a) Host-Guest Recognition where a receptor (host) forms a complex with a substrate (guest) and (b) Self-Assembly which involves the association of multiple components to construct some higher structure.
What are supramolecular materials? ›Supramolecular materials are architectures consisting of molecules that are able to self-assemble into larger constructs (Lehn, 2002). Polymers as well as small molecules are able to form self-assembled structures.
Is DNA a supramolecular structure? ›Various nano-sized supramolecular architectures have been constructed from DNA molecules via sequence-dependent self-assembly. A DNA three-way junction (3WJ), consisting of three oligonucleotides that are partially complementary to each other, is one of the simplest DNA supramolecular structures.
What is a supramolecular structure? ›Supramolecular structures are related to molecules in the same way that molecular structures are related to atoms. Although atoms play a critical role in the paradigms of chemistry, it is molecular structure that is generally at the center of the chemistry of many important technological and biological materials.
Why is supramolecular important? ›A supramolecular approach has been used extensively to create artificial ion channels for the transport of sodium and potassium ions into and out of cells. Supramolecular chemistry is also important to the development of new pharmaceutical therapies by understanding the interactions at a drug binding site.
How supramolecular structures are formed? ›
Two DNA strands form a helical supramolecular assembly through hydrogen bonding interactions that form between the bases. Thymine can hydrogen bond preferentially with adenine. Cytosine hydrogen bonds preferentially with guanine.
What is the strongest molecular interaction? ›Dipole-dipole interactions are the strongest intermolecular force of attraction.
What is molecular recognition of supramolecular? ›Chemists have demonstrated that many artificial supramolecular systems can be designed that exhibit molecular recognition. One of the earliest examples of such a system are crown ethers which are capable of selectively binding specific cations. However, a number of artificial systems have since been established.
What are molecular devices in supramolecular chemistry? ›A molecular device can be defined as an assembly of a discrete number of molecular components designed to achieve a specific function. Each molecular component performs a single act, while the entire supramolecular assembly performs a more complex function, which results from the cooperation of the various components.
What are the three types of molecular interactions? ›The three major types of intermolecular interactions are dipole–dipole interactions, London dispersion forces (these two are often referred to collectively as van der Waals forces), and hydrogen bonds.
What are the basic functions of supramolecular species? ›Thus, molecular recognition, transformation and translocation represent the basic functions of supramolecular species.
What is the impact factor of supramolecular? ›The 2022-2023 Journal's Impact IF of Supramolecular Chemistry is 2.23, which is just updated in 2023.
What are the applications of supramolecular chemistry? ›Supramolecular chemistry deals with the chemistry of the noncovalent bond between molecules and/or ionic species. Inspired by processes in Nature, synthetic receptors mimic biological recognition and regulation processes, and they are applied in catalysis, sensing and separation technologies.
Which structural unit is DNA built from? ›DNA is made up of monomeric molecules called nucleotides.
Are chromosomes supramolecular complexes? ›This study demonstrates that it is possible to explain this morphology by considering that chromosomes are self-organizing supramolecular structures formed by stacked layers of planar chromatin having different nucleosome-nucleosome interaction energies in different regions.
What is the difference between macromolecules and supramolecular? ›
Structure & Reactivity: Macromolecules. Supramolecular assemblies are a different type of large structure, related to macromolecules. In a supermolecular assembly, parts of the structure are held together by very strong interactions, but not necessarily by covalent bonds.
What is the nature of supramolecular? ›Supramolecular chemistry specializes in non-covalent interactions. These weak and reversible forces are key to understanding biological processes and self-assembling systems, and to constructing complex materials and molecular machinery.
What is the strongest possible chemical link? ›In chemistry, a covalent bond is the strongest bond, In such bonding, each of two atoms shares electrons that bind them together. For example - water molecules are bonded together where both hydrogen atoms and oxygen atoms share electrons to form a covalent bond.
What is the strongest molecular force of attraction? ›The strongest intermolecular force is hydrogen bonding, which is a particular subset of dipole-dipole interactions that occur when a hydrogen is in close proximity (bound to) a highly electronegative element (namely oxygen, nitrogen, or fluorine).
What are the two strongest interactions? ›Therefore, the order of strength of bonds from the strongest to weakest is; Ionic bond > Covalent bond > Hydrogen bond > Van der Waals interaction.
What are supramolecular forces? ›Supramolecular interactions are a class of interactions categorized by their non-covalent character. Examples of supramolecular interactions include van der Waals forces, pi-pi stacking, hydrogen bonding, metal-ligand coordination, electrostatic interactions, and host-guest interactions.
How do molecules interact with one another? ›Atoms with a positive charge will be attracted to negatively charged atoms to form a molecule. This bonding between atoms is the key to how molecules interact with each other. The positioning of atoms in a molecule may give it polarity.
What are the three major molecular bonds in living systems? ›There are four types of chemical bonds essential for life to exist: Ionic Bonds, Covalent Bonds, Hydrogen Bonds, and van der Waals interactions.
What is an example of molecular interaction? ›For example, in liquid water (where molecules are close together), all water molecules are polarized. The permanent dipole of each water molecule polarizes all adjacent water molecules. The dipole of a water molecule induces change in the dipoles of all nearby water molecule.
What is an example of supramolecular catalysis? ›An enzyme (TEV protease, PDB: 1lvb) is an example of supramolecular catalysts in nature.
What are supramolecular interactions in catalysis? ›
Supramolecular interactions that play a role in catalysis are hydrogen bonding,5 π–π stacking,6 hydrophobic interactions,7 anion–π interactions,8 cation–π interactions,9 Lewis-acid metal–ligand interactions, ion–dipole interactions,10 cation–anion attractions, Dewar–Chatt–Duncanson metal–ligand interactions, van der ...
What are the types of non-covalent interactions in supramolecular chemistry? ›Noncovalent interactions, including electrostatic, hydrogen-bonding, π–π stacking, and van der Waals interactions, are at the core of supramolecular chemistry.
Why is DNA an excellent example of a supramolecular self-assembly? ›Supramolecular DNA assembly†
The powerful self-assembly features of DNA make it a unique template to finely organize and control matter on the nanometre scale. While DNA alone offers a high degree of fidelity in its self-assembly , a new area of research termed 'supramolecular DNA assembly ' has recently emerged.
The most famous example is ferrocenium, [Fe(C 5H 5) 2]+, the blue iron(III) complex derived from oxidation of orange iron(II) ferrocene (few metallocene anions are known).
What are 5 examples of catalyst in real life situation? ›Almost everything in your daily life depends on catalysts: cars, Post-It notes, laundry detergent, beer. All the parts of your sandwich—bread, cheddar cheese, roast turkey. Catalysts break down paper pulp to produce the smooth paper in your magazine.
What are 5 examples of catalyst? ›- The manufacture of epoxyethane from ethene.
- The halogenation of benzene.
- The reaction with chlorine. The reaction with bromine.
- The Friedel-Crafts alkylation of benzene.
- The Friedel-Crafts acylation of benzene.
Thus, molecular recognition, transformation and translocation represent the basic functions of supramolecular species.
What is supramolecular function? ›Supramolecular chemistry deals with the chemistry and collective behavior of organized ensembles of molecules. In this so-called mesoscale regime, molecular building blocks are organized into longer-range order and higher-order functional structures via comparatively weak forces.
What are the various forces involved in supramolecular chemistry? ›Supramolecular structures are a result of various noncovalent interactions, including van der Waals interaction, electrostatic interaction, hydrogen bonding, hydrophobic interaction, coordination, etc., some of which are often cooperatively working in one supramolecular complex.
What are the types of bonding in supramolecular chemistry? ›While traditional chemistry concentrates on the covalent bond, supramolecular chemistry examines the weaker and reversible non-covalent interactions between molecules. These forces include hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi–pi interactions and electrostatic effects.
What are the four types of bonds or interactions these are? ›
There are four types of bonds or interactions: ionic, covalent, hydrogen bonds, and van der Waals interactions.
What is molecular recognition in supramolecular chemistry? ›Molecular recognition is the specific interaction between two or more molecules, which exhibit molecular complementarity, through noncovalent bonding such as hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, π–π interactions, and/or electrostatic effects.
Is DNA a supramolecular? ›(22,23) DNA hybridization is a typical form of supramolecular assembly. Besides, as summarized in this Account, micro/nanointerfaces are constructed through various noncovalent interactions between DNA and other components, such as electrostatic attraction and π–π stacking aptamer recognition and coordination.