Academic literature on the topic 'Bioinspired Confined Catalysis'

Correction for ‘Bioinspired hydrogel-based nanofluidic ionic diodes: nano-confined network tuning and ion transport regulation’ by Congcong Zhu et al., Chem. Commun., 2020, 56, 8123–8126, DOI: 10.1039/D0CC01313G.

The biological ion channel-based mass transport and signal transduction play a crucial role in physiological activities, and the biomimetic nanochannels with nanoconfined hydrogel network for ion transport have been extensively studied.

AbstractAnion‐π catalysis operates by stabilizing anionic transition states on π‐acidic aromatic surfaces. In anion‐(π)n‐π catalysis, π stacks add polarizability to strengthen interactions. In search of synthetic methods to extend π stacks beyond the limits of foldamers, the self‐assembly of micelles from amphiphilic naphthalenediimides (NDIs) is introduced. To interface substrates and catalysts, charge‐transfer complexes with dialkoxynaphthalenes (DANs), a classic in supramolecular chemistry, are installed. In π‐stacked micelles, the rates of bioinspired ether cyclizations exceed rates on monomers in organic solvents by far. This is particularly impressive considering that anion‐π catalysis in water has been elusive so far. Increasing rates with increasing π acidity of the micelles evince operational anion‐(π)n‐π catalysis. At maximal π acidity, autocatalytic behavior emerges. Dependence on position and order in confined micellar space promises access to emergent properties. Anion‐(π)n‐π catalytic micelles in water thus expand supramolecular systems catalysis accessible with anion‐π interactions with an inspiring topic of general interest and great perspectives.

AbstractAnion‐π catalysis operates by stabilizing anionic transition states on π‐acidic aromatic surfaces. In anion‐(π)n‐π catalysis, π stacks add polarizability to strengthen interactions. In search of synthetic methods to extend π stacks beyond the limits of foldamers, the self‐assembly of micelles from amphiphilic naphthalenediimides (NDIs) is introduced. To interface substrates and catalysts, charge‐transfer complexes with dialkoxynaphthalenes (DANs), a classic in supramolecular chemistry, are installed. In π‐stacked micelles, the rates of bioinspired ether cyclizations exceed rates on monomers in organic solvents by far. This is particularly impressive considering that anion‐π catalysis in water has been elusive so far. Increasing rates with increasing π acidity of the micelles evince operational anion‐(π)n‐π catalysis. At maximal π acidity, autocatalytic behavior emerges. Dependence on position and order in confined micellar space promises access to emergent properties. Anion‐(π)n‐π catalytic micelles in water thus expand supramolecular systems catalysis accessible with anion‐π interactions with an inspiring topic of general interest and great perspectives.

Numerous reported bioinspired osmotic energy conversion systems employing cation‐/ anion‐selective membrane and solutions with different salinity are actually far from the biological counterpart. The iso‐osmotic power generator with the specific ionic permselective channels (e.g., K+ or Na+ channels) which just allow specific ions get across and iso‐osmotic solutions still remain challenges. Inspired by nature, we report a bioinspired K+‐channel by employing a K+ selective ligand, 1,1,1‐tris{[(2’‐benzylaminoformyl)phenoxy]methyl}ethane (BMP) and graphene oxide membrane. Specifically, the K+ and Na+selectivity of the prepared system could reach up to ~17.8, and the molecular dynamics simulation revealed that the excellent permselectivity of K+ is mainly stemmed from the formed suitable channel size. Thus, we assembled the K+‐selective iso‐osmotic power generator (KSIPG) with the power density up to ~15.1 mW/m2 between equal concentration solutions, which is higher than traditional charge‐selective osmotic power generator (CSOPG). The proposed strategy has well shown the realizable approach to construct single‐ion selective channels‐based highly efficient iso‐osmotic energy conversion systems and would surely inspire new applications in other fields, including self‐powered system and medical materials, etc.

Stress response, an intricate and autonomously coordinated reaction in living organisms, holds a reversible, multi‐path, and multi‐state nature. However, existing stimuli‐responsive materials often exhibit single‐step and monotonous reactions due to the limited integration of structural components. Inspired by the cooperative interplay of extensor and flexor cells within Mimosa's pulvini, we present a hydrogel with differentiated hydrogen‐bonding (H‐bonding) networks designed to enable the biological stress response. Weak H‐bonding domains resemble flexor cells, confined within a hydrophobic network stabilized by strong H‐bonding clusters (acting like extensor cells). Under external force, strong H‐bonding clusters are disrupted, facilitating water diffusion from the bottom layer and enabling transient expansion pressure gradient along the thickness direction. Subsequently, water diffuses upward, gradually equalizing the pressure, while weak H‐bonding domains undergo cooperative elastic deformation. Consequently, the hydrogel autonomously undergoes a sequence of reversible and pluralistic motion responses, similar to Mimosa's touch‐triggered stress response. Intriguingly, it exhibits stress‐dependent color shifts under polarized light, highlighting its potential for applications in time‐sensitive "double‐lock" information encryption systems. This work achieves the coordinated stress response inspired by natural tissues using a simple hydrogel, paving the way for substantial advancements in the development of intelligent soft robots.

AbstractAccelerating the conversion of soluble lithium polysulfides (LiPSs) to solid Li2S2/Li2S through single‐atom cathodes has emerged as a promising strategy for realizing high‐performance lithium–sulfur batteries. However, rationally optimizing the conversion effects and spatial capture abilities of LiPSs intermediates on the atomic catalytic sites is extremely required but still faces enormous challenges. Here, inspired by the delicate structure of sieve tubes in plants, Fe single‐atom cathode (channel‐FeSAC) equipped with long‐range ordered channels and localized capture‐catalysis microenvironments towards efficient LiPSs conversion is reported on designing. Benefiting from the individual and stable catalytic areal for localized capture and migration inhibition abilities on LiPSs and fully confined triple‐phase boundaries between atomic catalytic centers, conductive carbon, and electrolytes, the channel‐FeSAC can effectively convert polysulfides, thus eliminating the shuttle effects and generation of inactive LiPSs. It is also elucidated that the channel‐FeSAC exhibits superior migration inhibition of polysulfide and accelerates Li2S deposition/conversion kinetics compared with bowl‐FeSAC and flat‐FeSAC. The outstanding areal capacity and cycling stability under high sulfur loading and low electrolyte/sulfur ratio verify that the channel‐FeSAC holds great potential as cathodes for high‐performance cathodes. This work offers vital insights into the essential roles of bioinspired fully confined channels and catalytic microenvironments in polysulfide catalysis for efficient lithium–sulfur batteries.

Reproducing the key features offers by metalloprotein binding cavities is an attractive approach to overcome the main bottlenecks of curent open artificial models (in terms of stability, efficiency and selectivity)....

L’objectif de ces travaux de thèse est le développement de nouveaux ligand-cages hémicryptophanes pour l’obtention de catalyseurs métalliques confinés. Ces catalyseurs seront utilisés pour l’activation bioinspirée d’O2 et la fonctionnalisation C-H en milieu confiné. Le design des cages cibles vise à introduire des ligands bioinspirés pour la coordination de métaux biologiques (Cu, Fe, Zn). La structure hémicryptophane offre une cavité hydrophobe au voisinage du site actif métallique. Cette structure vise à stabiliser les espèces actives et obtenir des réactivités différentes de celles obtenues avec les modèles ouverts correspondants. Dans ce contexte, l’objectif principale de ce travail a été d’obtenir des complexes de cuivre confinés capable d’activer l’oxygène moléculaire pour accomplir des réactions difficiles de fonctionnalisation C-H. La première partie de cette thèse consiste en étude bibliographique de (i) les précédentes applications des hémicryptophanes et (ii) les progrès récents sur les complexes bioinspirés encagés. Ensuite, nos complexes de cuivres à ligands tris(pyridyl)amine (TPA) ouverts et encagés, ont été étudiés pour l’activation d’O2 et pour des réactions non-usuelle de fonctionalisation de liaisons C-H. Nous avons ensuite préparé et étudié une nouvelle cage TPA-hemicryptophane équipée d’une cavité donneuse de liaisons hydrogène C(triazole)-H. Cette cavité fonctionnalisée vise à reproduire les cavités des métalloprotéines. Enfin, des hémicryptophanes basés sur le ligand triazacyclononane (TACN), ont été préparé pour la première fois. L’objectif de ces nouveaux ligand-cages est de contribuer au développement de complexes bioinspirés à Cu et Fe pouvant, par exemple, activer O2
This thesis aims at developing new hemicryptophane cage-ligands to obtain confined metal-based catalysts for bioinspired O2 activation and C-H bond functionalization in confined space. The design of the targeted cages aims at introducing ligands inspired from metalloproteins active sites, for coordination of biorelevant metals (Cu, Fe, Zn). Importantly, the hemicryptophane structure provide a hydrophobic cavity around the active metal core. This structure aims at stabilizing highly reactive intermediates and reaching different reactivity compare to open model complexes, devoid of cavity. In this context, a major objective of this work was to reach Cu-based bioinspired catalysts able to activate molecular oxygen for challenging C-H bond functionalization. The first part of the thesis consists in a comprehensive literature survey on (i) background of previous applications of hemicryptophane cages and (ii) recent advances in caged bioinspired complexes. The application of our open and caged Cu-complex, based on the tris(pyridyl)amine (TPA) ligand is next described. These catalysts have been used for O2 activation and unusual intramolecular C-H bond functionalization. We then prepare and studied a new TPA-hemicryptophane cage equipped with a C(triazole)-H hydrogen bonding cavity. This functionalized cavity aims at reproducing the binding cavities found in metalloproteins. Finally, hemicryptophane cages based on the triazacyclononane (TACN) ligand have been prepared for the first time. The goal of these cage-ligands is to develop new bioinspired Cu and Fe complexes that could be, for instance, used as O2 activating catalysts

Nanomaterials (NMs) developed using biomolecules display numerous advantages which attract the science community to explore them for a wide range of applications. In this line, bio-scaffolds are studied as templates to form nano-bio heterojunctions in the nano confined materials. With the high flexibility of biomediated NMs, it is possible to develop desired size and shape selective NMs. Such bio-based NMs have great benefits in wide areas including catalysis, sensors and energy related applications particularly, electrocatalysis, supercapacitor, batteries etc. The viability of bio-scaffolds in developing metal superstructures makes them better choice in the medicinal fields. This book chapter mainly focused on the advantageous and challenges of bioinspired NMs in the medicinal field, particularly in drug delivery systems. Moreover, the synthetic methods such as enzyme catalyzed wet-chemical route, photo-irradiation and incubation methods were also discussed in detail. Also, this chapter gives a better understanding to the readers about the development of new nano-bio heterojunctions for medicine, energy and environmental fields. Moreover, the morphological features of nano-bio interactions at nanoscale level show predominant activity particularly in Surface Enhanced Raman Scattering (SERS) and sensor applications. With the knowledge gained from this chapter, in futuristic, one can go for the development of new metal nanostructures with different bio-scaffolds such as microorganisms, viruses, DNA and protein to mainstream applications for the medicinal fields.