Mechanically Interlocked Aerogels with Densely Rotaxanated Backbones

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(25), С. 11434 - 11443

Опубликована: Июнь 13, 2022

Mechanically interlocked molecules are considered promising candidates for the construction of self-adaptive materials by virtue their fascinating structural and dynamic features. However, it is still a great challenge to fabricate such with higher complexity richer functionality. Herein, we propose concept mechanically aerogels (MIAs) in which three-dimensional (3D) porous frameworks made dense modules, thereby enabling integration mechanical adaptivity multifunctionality single entity. The lightweight MIA monoliths possess good appearance hierarchical meso- submicron-pores. Profiting from combination bonds skeletons aerogels, our MIAs not only robust (average Young's modulus = 5.80 GPa specific 130.5 kN·m/kg) but also showcase favorable responsiveness under external stimuli. Taking advantage above integrative merits, demonstrate terms iodine uptake, thermal insulation, selective adsorption organic dyes. Our work opens door designing intelligent delicate topological chemical structures while facilitating development materials.

Язык: Английский

---

Self-Assembly and Photothermal Conversion of MetallaRussian Doll and Metalla[2]catenanes Induced via Multiple Stacking Interactions

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(32), С. 18036 - 18047

Опубликована: Июль 17, 2023

A variety of organometallic supramolecular architectures have been constructed over the past decades and their properties were also explored via different strategies. However, synthesis metalla-Russian doll is still a fascinating challenge. Herein, series new coordination complexes, including doll, metalla[2]catenanes, metallarectangles, synthesized by using meticulously selected Cp*Rh (Cp* = η5-C5Me5) building units (E1, E2, E3) three rigid anthracylpyridine ligands (L1, L2, L3) self-assembly strategy. While combination short ligand L1 E1 or E2 generated two longer L2 containing an alkynyl group resulted in [2]catenanes, most likely due to which strong electron-donating effect groups causes self-accumulation. Interestingly, unusual Russian assembly was obtained through reaction L3 E3 based on sextuple π···π stacking interactions. Furthermore, dynamic structural conversion between [2]catenanes corresponding metallarectangles could be observed concentration-, solvent-, guest-induced effects. The [2]catenane complexes 4b displayed efficient photothermal efficiency solution (20.2%), comparison with other macrocycles. We believe that interactions generate active nonradiative pathways promote radiative photodeactivation pathways. This study proves versatility half-sandwich units, not only build complicated topologies but effective functional materials for various appealing applications.

Язык: Английский

---

Cation-Templated Assembly of 6₁³ and 6₂³ Metalla-Links

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(8), С. 4746 - 4756

Опубликована: Янв. 30, 2023

Facilitated by multiple stacking interactions between components, two kinds of metalla-links containing molecular Borromean rings (623 links) and head-to-tail cyclic [3]catenanes (613 links), as isomers, were constructed in high yield introducing tri-μ-methoxyl-dinuclear complexes [(Cp*M)2(μ-OCH3)3][OTf] (M = RhIII or IrIII, Cp* η5-pentamethylcyclopentadienyl, OTf triflate) unusual cationic guests during coordination-driven assembly. The topology these intricate structures was controlled strategically selecting dipyridyl ligands that differ their coordination orientations, evidenced X-ray crystallography electrospray ionization-time-of-flight/mass spectrometry analysis. behavior the abovementioned solution monitored further studied detailed NMR techniques.

Язык: Английский

---

Selective Construction and Structural Transformation of Homogeneous Linear Metalla[4]catenane and Metalla[2]catenane Assemblies

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(18)

Опубликована: Фев. 7, 2024

Abstract Although the synthesis of mechanically interlocked molecules has been extensively researched, selectively constructing homogeneous linear [4]catenanes remains a formidable challenge. Here, we constructed metalla[4]catenane in one‐step process through coordination‐driven self‐assembly bidentate benzothiadiazole derivative ligand and binuclear half‐sandwich rhodium precursor. The formation metalla[4]catenanes was facilitated by cooperative interactions between strong sandwich‐type π‐π stacking non‐classical hydrogen bonds components. Moreover, modulating aromatic substituents on precursor, two metalla[2]catenanes were obtained. molecular structures these metallacatenanes unambiguously characterized single‐crystal X‐ray diffraction analysis. Additionally, reversible structural transformation metal‐catenanes corresponding metallarectangles could be achieved altering their concentration, as confirmed mass spectrometry NMR spectroscopy studies.

Язык: Английский

---

Selective separation of planar and non-planar hydrocarbons using an aqueous Pd₆ interlocked cage

Chemical Science, Год журнала: 2022, Номер 13(40), С. 11764 - 11771

Опубликована: Янв. 1, 2022

We report here a triply interlocked cage with the ability to encapsulate planar guests in aqueous medium. This property was then employed efficiently separate and non-planar aromatic hydrocarbons by extraction.

Язык: Английский

---

An Organo‐Palladium Host Built from a Dynamic Macrocyclic Ligand: Adaptive Self‐Assembly, Induced‐Fit Guest Binding, and Catalysis

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(42)

Опубликована: Авг. 29, 2022

Artificial hosts with rich conformational dynamics are attractive to supramolecular chemists due their adaptive guest-binding properties and enzyme-like catalytic functions. We report here the self-assembly host-guest catalysis of a new water-soluble organo-palladium host (Pd2 L2 ) built from pyridinium-bonded macrocyclic ligand (L) cis-blocked palladium corners (Pd). While direct L Pd gives rise dynamic mixture products, both neutral polyaromatic hydrocarbons an anionic polyoxometalate cluster (W10 O324- can template dominant formation Pd2 host. Guest-adaptive changes induced-fit cavity deformation have been clearly observed in crystal structures. Moreover, installation electron-rich W10 within cationic redox-active O32 ⊂Pd2 facilitates efficient selective C-H photooxidation toluene derivatives aldehyde products under mild conditions, thus representing ideal platform for green catalysis.

Язык: Английский

---

Selective Synthesis and Structural Transformation of a 4‐Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(20)

Опубликована: Март 17, 2023

Intricately interwoven topologies are continually being synthesized and ultimately equally versatile significant at the nanoscale level; however, reports concerning ravel structures, which highly entwined new topological species, extremely rare fraught with tremendous synthesis challenges. To solve problem, a tetrapodontic pyridine ligand L1 two types of olefinic bond units Cp*M-based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform self-assembly. Two unprecedented [5+10] icosanuclear molecular 4-ravels containing four crossings were obtained by parallel-displaced π⋅⋅⋅π interactions in single-step strategy. Remarkably, reversible structural transformations between 4-ravel corresponding metallocage could be realized concentration changes solvent- guest-induced effects. X-ray crystallographic data NMR spectroscopy provide full confirmation these phenomena.

Язык: Английский

---

Cross-catenation between position-isomeric metallacages

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Фев. 14, 2024

Abstract The study of cross-catenated metallacages, which are complex self-assembly systems arising from multiple supramolecular interactions and hierarchical assembly processes, is currently lacking but could provide facile insights into achieving more precise control over low-symmetry/high-complexity systems. Here, we report a cross-catenane formed between two position-isomeric Pt(II) metallacages in the solid state. These [2]catenanes solution, whereas 1:1 mixture selectively crystals. Varied temperature nuclear magnetic resonance experiments time-of-flight mass spectra employed to characterize cross-catenation solutions, dynamic library shown. Additionally, searched for global-minimum structures three re-optimized low-lying using density functional theory calculations. Our results suggest that binding energy cross-catenanes significantly larger than self-catenanes within library, selectivity crystallization thermodynamic. This presents different may insight development self-assemble

Язык: Английский

---

The End of the Beginning of Mechanical Stereochemistry

Accounts of Chemical Research, Год журнала: 2024, Номер 57(12), С. 1696 - 1708

Опубликована: Июнь 3, 2024

ConspectusStereochemistry has played a key role in the development of synthetic chemistry for simple reason that function and properties most molecules, from medicine to materials science, depend on their shape thus stereoisomer used. However, despite potential rotaxanes catenanes display unusual forms stereochemistry being identified as early 1961, this aspect mechanical bond remained underexplored underexploited; until 2014 it was only possible access chiral whose stereoisomerism is solely attributable using stationary phase high performance liquid chromatography, which limited production scale inhibited investigation applications. Furthermore, stereogenic units such molecules analogues were often poorly described, made hard fully articulate both what had been achieved field problems left solve. Relatively recently, methods selectively have developed, making these intriguing structures available study range prototypical applications including catalysis, sensing, luminophores.In Account, we briefly discuss history stereochemistry, beginning 1961 when first identified, before defining how arises structural point view. Building this, stereochemical arguments, confirm complete set unique two-component finally categorized unambiguously, with last 2024. After pausing some curiosities arise contain covalent units, due co-conformational movement, use our framework summarize efforts develop conceptually general approaches [2]catenanes [2]rotaxanes containing all units. In particular, highlight nature unit affects strategies stereoselective synthesis. We finish by highlighting recent chemical interlocked rely discussing future directions challenges.Taken together, propose transition make stereopurity clearly articulated methodological concepts suggests maturing. Thus, are now coming end stereochemistry. The stage play functional areas, indeed any or physical application where control over molecular required.

Язык: Английский

---

The Final Stereogenic Unit of [2]Rotaxanes: Type 2 Geometric Isomers

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(12), С. 8472 - 8479

Опубликована: Март 18, 2024

Mechanical stereochemistry arises when the interlocking of stereochemically trivial covalent subcomponents results in a complex object. Although this general concept was identified 1961, stereochemical description these molecules is still under development to extent that new forms mechanical are being identified. Here, we present simple analysis rotaxane and catenane allowed us identify final missing stereogenic unit, an overlooked form geometric isomerism, demonstrate its stereoselective synthesis.

Язык: Английский

---