A Three‐Dimensional Dynamic Supramolecular “Sticky Fingers” Organic Framework

Abstract

Engineering high-recognition host-guest materials is aburgeoning area in basic and applied research. The challenge of exploring novel porous materials with advanced functionalities prompted us to develop dynamic crystalline structures promoted by soft interactions.T he first example of ap ure molecular dynamic crystalline framework is demonstrated, which is held together by means of weak "stickyf ingers" van der Waals interactions.T he presented organic-fullerene-based material exhibits an on-porous dynamic crystalline structure capable of undergoing single-crystal-to-single-crystal reactions.E xposure to hydrazine vapors induces structural and chemical changes that manifest as toposelective hydrogenation of alternating rings on the surface of the [60]fullerene.Control experiments confirm that the same reaction does not occur when performed in solution. Easy-to-detect changes in the macroscopic properties of the sample suggest utility as molecular sensors or energy-storage materials.One of the important challenges in chemical science nowadays is the search for greener processes for ac leaner world. [1] In chemistry,t his usually translates into highly selective reactions with high rates and efficiencies. [2] Recently, novel synthetic strategies were proposed that diverge from classical approaches.While the latter are usually based on the temperature,p ressure,a nd exact formulation control, reac-tivity control of the former explores novel environmental strategies (for example,t he successful surface chemistry approach, [3] chemical topology, [4] or chemical reactions performed in confined spaces [5] in which the reactivity differs in many aspects from those conducted in bulk solution). In that sense,p orous materials connected by intermolecular bonds (such as,m etal-organic frameworks [6] (MOFs), covalent organic frameworks [7] (COFs), or porous molecular materials [8] that are built from discrete molecules [9] such as porous organic cages) [10] have provided notable results.The discovery and development of these materials has spurred an interest in confined chemical reactions to determine how spatial confinement can influence the yields and reactivity pathways of reactions. [11] MOFs offer improved flexibility compared to rigid zeolites and less processable COFs. [12] This flexibility could generate novel dynamic adsorption properties under realistic conditions-similar to the liquid-protein reactions that occur for specific interactions between an enzymatic host and as ubstrate.P ure organic systems usually demonstrate excellent properties,s uch as high thermal stabilities,t unable structural properties,a nd biocompatibility;h owever,t hey also present drawbacks,s uch as rigidity and limited processability.T herefore,t he formation of dynamic structures (porous or non-porous acting as porous) by means of supramolecular interactions between molecules might be an interesting alternative.H owever,t he crystallization of stable organic structures possessing porosity or showing the ability to incorporate molecules by...

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