In situ monitoring of mechanochemical covalent organic framework formation reveals templating effect of liquid additive

•In situ monitoring of mechanochemical formation 2D covalent organic frameworks•Experimental evidence templating effect by liquid additive•Relevance additive selection, catalyst choice, and activation procedure Covalent frameworks (COFs) are materials increasing interest due to their structural diversity, molecular precision, promise for applications in gas storage, optoelectronics, catalysis, beyond. To make full use these also beyond laboratories, a better understanding the development efficient reliable methods scalable synthesis is key. Solvent-free COFs an auspicious preparation technique toward this goal. Our study on COF highlights X-ray powder diffraction as viable gaining unique insights into mechanism COFs. We reveal key intermediates liquid-assisted grinding reactions influence kinetics microstructural features. This bodes well rational design opens up path environmentally friendly synthesis. have emerged new class molecularly precise, porous functional characterized broad chemical versatility, with diverse range applications. Despite popularity, fundamental aspects poorly understood, lacking profound experimental assembly. Here, we combination Raman spectroscopy elucidate reaction imine COFs, leading observation that offer direct framework through additives. Moreover, solid-state scandium triflate instrumental directing mechanism, yielding crystallinity porosity par solvothermal products. work provides first solvent-based significant advancement mechanistic mechanochemistry green route emergent solids, whose advanced properties result from tunable, precise backbone, paired crystallinity.1Lohse M.S. Bein T. frameworks: structures, synthesis, applications.Adv. Funct. Mater. 2018; 28: 1705553Crossref Scopus (632) Google Scholar,2Yaghi O.M. Reticular chemistry all dimensions.ACS Cent. Sci. 2019; 5: 1295-1300Crossref PubMed (94) Scholar The reticular assembly building blocks inherently different sizes, shapes, flexibility two- (2D) or three-dimensional (3D) increasingly complex structures topologies allows tailored targeted properties. so far proposed many, including storage separation,3Gottschling K. Stegbauer L. Savasci G. Prisco N.A. Berkson Z.J. Ochsenfeld C. Chmelka B.F. Lotsch B.V. Molecular carbon dioxide sorption hydrazone-based tertiary amine moieties.Chem. 31: 1946-1955Crossref (47) Scholar, 4Furukawa H. Yaghi Storage hydrogen, methane, highly clean energy applications.J. Am. Chem. Soc. 2009; 131: 8875-8883Crossref (1845) 5Yu J.T. Chen Z. Sun J. Huang Z.T. Zheng Q.Y. Cyclotricatechylene based crystalline material: storage.J. 2012; 22: 5369-5373Crossref (112) heterogeneous catalysis,6Xu Gao Jiang D. Stable, crystalline, porous, platform chiral organocatalysts.Nat. 2015; 7: 905-912Crossref (842) 7Mu M. Wang Y. Qin Yan X. Li Two-dimensional imine-linked selective oxidation olefins.ACS Appl. Interfaces. 2017; 9: 22856-22863Crossref (91) 8Xu Lin Addicoat Irle S. Catalytic via pore surface engineering.Chem. Commun. (Camb). 2014; 50: 1292-1294Crossref 9Ding S.Y. Q. Zhang Song W.G. Su C.Y. W. Construction catalysis: Pd/COF-LZU1 Suzuki–Miyaura coupling reaction.J. 2011; 133: 19816-19822Crossref (1498) photocatalysis,10Banerjee Haase F. Gottschling Single-site photocatalytic H2 evolution cobaloxime co-catalysts.J. 139: 16228-16234Crossref (191) 11Wang Chong Little M.A. Wu Zhu W.H. Clowes R. Zwijnenburg Sprick R.S. Cooper A.I. Sulfone-containing hydrogen water.Nat. 10: 1180-1189Crossref (502) 12Biswal B.P. Vignolo-González H.A. Banerjee Grunenberg Nuss Sustained solar thiazolo[5,4-d]thiazole-bridged nickel-thiolate Cluster water.J. 141: 11082-11092Crossref (134) fuel cells,13Aiyappa H.B. Thote Shinde D.B. Kurungot Cobalt-modified robust water electrocatalyst.Chem. 2016; 4375-4379Crossref (247) Scholar,14Lin Zhao Xia Design principles electrocatalysts conversion oxidizer production.Adv. 29: 1606635Crossref (117) sensing.15Singh Tomer V.K. Jena N. Bala I. Sharma Nepak De Sarkar A. Kailasam Pal S.K. A truxene-based its application humidity sensing.J. 21820-21827Crossref 16Li Yang C.X. X.P. versatile framework-based sensing biomolecules.Chem. 53: 11469-11471Crossref 17Zhou Zhong Cui Zhuang Bi Yu bearing thioether pendant arms detection recovery Au ultra-low concentration aqueous solution.Chem. 54: 9977-9980Crossref typically synthesized solution methods, e.g., solvothermally, sonochemically, microwave irradiation, continuous flow,18Peng Wong W.K. Hu Cheng Yuan Khan S.A. Room temperature batch flow water-stable (COFs).Chem. 5095-5101Crossref (158) and, more recently, electron beam irradiation19Zhang Zhou He Sheridan M.V. Dai et al.Electron irradiation general approach rapid under ambient conditions.J. 2020; 142: 9169-9174Crossref (34) mechanochemistry.20Biswal Chandra Kandambeth Lukose B. Heine Mechanochemical chemically stable isoreticular frameworks.J. 2013; 135: 5328-5331Crossref (562) 21Das Balaji Biswal Mechanosynthesis imine, ?-ketoenamine, hydrogen-bonded using grinding.Chem. 12615-12618Crossref 22Shinde Aiyappa Bhadra Wadge P. Garai Kundu mechanochemically proton-conducting solid electrolyte.J. 4: 2682-2690Crossref 23Karak Sasmal H.S. Kumar Pachfule Constructing ultraporous seconds terracotta process.J. 1856-1862Crossref (254) Mechanochemistry, i.e., mechanical agitation conduct sustain transformations, has recently been established cornerstone green, solvent-free chemistry.24Friš?i? Mottillo Titi H.M. Mechanochemistry synthesis.Angew. Int. Ed. Engl. 59: 1018-1029Crossref (328) 25James S.L. Adams C.J. Bolm Braga Collier Friš?i? Grepioni Harris K.D.M. Hyett Jones al.Mechanochemistry: opportunities cleaner synthesis.Chem. Rev. 41: 413-447Crossref (26) 26DeSantis Mason J.A. James B.D. Houchins Long J.R. Veenstra Techno-economic analysis metal-organic natural storage.Energy Fuels. 2024-2032Crossref (177) successfully applied wide reactions, nanoparticles,27Baláž Achimovicová Baláž Billik Cherkezova-Zheleva Criado J.M. Delogu Dutková E. Gaffet Gotor F.J. al.Hallmarks mechanochemistry: From nanoparticles technology.Chem. 42: 7571-7637Crossref (785) cages,28Leonardi Villacampa Menéndez J.C. Multicomponent 2042-2064Crossref small molecules,29Bruckmann Krebs Organocatalytic reactions: effects ball milling, ultrasound irradiation.Green 2008; 1131-1141Crossref (282) cocrystals,30Friš?i? Recent advances cocrystal grinding.Cryst. Growth Des. 1621-1637Crossref (568) Scholar,31Hasa Screening pharmaceutical forms practical guide.Adv. Drug Deliv. 117: 147-161Crossref electrolytes,32Kosova N.V. Uvarov N.F. Devyatkina E.T. Avvakumov E.G. LiMn2O4 cathode material lithium batteries.Solid State Ionics. 2000; 107-114Crossref (78) coordination polymers,33Cappuccino Farinella Maini easy boost CuI pyrazine polymers.Cryst. 19: 4395-4403Crossref (6) (MOFs)34Katsenis A.D. Puškari? Štrukil V. Julien P.A. Užarevi? Pham M.H. Do T.O. Kimber S.A.J. Lazi? al.In reveals topology framework.Nat. 6: 6662Crossref (215) COFs.20Biswal Synthesis not only accessing new, metastable phases34Katsenis but superior screen explore phase landscape polymorphs solids.35Hasa Miniussi multicomponent crystals: one polymorph? myth dispel.Cryst. 16: 4582-4588Crossref (83) Scholar,36Germann L.S. Arhangelskis Etter Dinnebier R.E. Challenging Ostwald rule stages cocrystallisation.Chem. 11: 10092-10100Crossref Bulk usually performed either reactants (neat grinding) presence minuscule amounts additives, (LAG).37Friš?i? Childs Rizvi S.A.A. role solvent sonochemical formation: solubility-based predicting cocrystallisation outcome.CrystEngComm. 418-426Crossref (381) Recently, studies facilitated synchrotron (XRPD),38Friš?i? Halasz Beldon P.J. Belenguer A.M. Honkimäki Real-time milling reactions.Nat. 66-73Crossref (405) Scholar,39Halasz Nightingale R.C. In real-time diffraction.Nat. Protoc. 8: 1718-1729Crossref (102) spectroscopy,40Gracin Laboratory spectroscopy.Angew. 6193-6197Crossref (133) Scholar,41Batzdorf Fischer Wilke Wenzel K.J. Emmerling Direct investigation combined 1799-1802Crossref (159) absorption spectroscopy,42de Oliveira P.F.M. Michalchuk A.A.L. Buzanich A.G. Bienert Torresi R.M. Camargo P.H.C. Tandem scattering forin situtime-resolved gold nanoparticle mechanosynthesis.Chem. 56: 10329-10332Crossref nuclear magnetic resonance (ssNMR),43Schiffmann J.G. Martins I.C.B. Van Wüllen In-situ mill state NMR.Solid Nucl. Magn. Reson. 109: 101687Crossref (14) and/or thermal measurements.44Užarevi? Exploring diffraction.Cryst. 2342-2347Crossref (71) enabled progress processes discovery materials.45Užarevi? playground chemists.J. Phys. Lett. 4129-4140Crossref (118) Although established, time-resolved rare. While previous mostly focused characterization,46Haase Germann Gutzler Duppel Vyas V.S. Kern Tuning stacking behaviour non-covalent interactions.Mater. Front. 1: 1354-1361Crossref 47Ascherl Sick Margraf Lapidus S.H. Calik Hettstedt Karaghiosoff Döblinger Clark Chapman K.W. al.Molecular docking sites designed generation frameworks.Nature 310-316Crossref (308) 48Zhang Y.B. Furukawa Yun Gándara Duong Zou Single-crystal structure framework.J. 16336-16339Crossref (280) post-synthetic modifications, transformations COFs,49Haase Troschke Dörfler Grundei M.M.J. Burow Kaskel Topochemical imine- thiazole-linked enabling real analysis.Nat. 2600Crossref (128) 50Jadhav Fang Liu C.H. Dadvand Hamzehpoor Patterson Jonderian Stein Perepichka D.F. Transformation between 3D reversible [2 + 2] cycloaddition.J. 8862-8870Crossref (53) 51Du Calabro Wooler Cundy Kamakoti Colmyer Mao Ravikovitch Kinetic COF-1 change staggered eclipsed model upon partial removal mesitylene.J. 118: 399-407Crossref (23) handful reports investigated underlying crosslinking, particle growth, self-assembly processes.52Li Chavez Dichtel W.R. Bredas J.L. Nucleation growth solution: example COF-5.J. 16310-16318Crossref 53Castano Evans Vitaku Strauss M.J. Brédas Gianneschi N.C. Chemical control over nucleation anisotropic two-dimensional frameworks.ACS 1892-1899Crossref (27) 54Smith B.J. Hwang Novotney rates stability boronate ester frameworks.Chem. 51: 7532-7535Crossref 55Li R.L. Flanders Ji Castano L.X. Controlled nanoparticles.Chem. 3796-3801Crossref 56Koo B.T. Heden R.F. Clancy polymerization crystallization monomers.Phys. 9745-9754Crossref 57Feriante Jhulki Barlow Marder S.R. New 18637-18644Crossref (29) report XRPD spectroscopy. library four hexagonal C2 C3 linkers were chosen systems (Scheme 1), system (COF-LZU1) previously prepared mechanochemically.20Biswal product investigated, revealing pronounced formation, regarding both experiments led intermediates, which provided additive, highlighting critical importance molecules during measurements 60 keV (? = 0.207 Å) at Powder Diffraction Total Scattering Beamline P02.1 Deutsches Elektronen-Synchrotron (DESY),58Dippel A.C. Liermann H.P. Delitz Walter Schulte-Schrepping Seeck O.H. Franz PETRA III high-resolution high-energy diffraction.J. Synchrotron Radiat. 675-687Crossref (129) modified Retsch MM400 operating frequency 30 Hz.38Friš?i? carried out custom-made 5 mL volume transparent poly(methyl methacrylate) (PMMA) jars, direct, time resolution 10 20 s. used aldehyde linkers, forming 1). Reactions 7 mm diameter stainless steel (1.38 g weight), 1,4-dioxane/mesitylene mixture (1:1 v/v) acetic acid (AcOH) scandium(III) (Sc(OTf)3) catalyst. optimal conditions extensively screened prior beamtime maximizing measured intensities as-synthesized laboratory measurements. step was crucial improve signal weakly light-element-based sufficiently real-time, (Figures S6–S11 Supplemental procedure). COF-LZU19Ding p-phenylenediamine (pPDA) 1,3,5-triformylbenzene (Tb) AcOH ratio reactant weight (?-parameter)37Friš?i? 0.60 ?L/mg. Unexpectedly, COF-LZU1 proceeded intermediate (1), visible appearance Bragg reflections 2.3°, 2.4°, 2.5°, 3.2° 2? (Figure 1A). unknown later identified ex spectroscopic techniques S1, S33–S34, S37–S38). readily followed integrating most intense 100 reflection intermediate. formed immediately grinding, simultaneously loss pPDA signal, traces Tb observable after ca. 3 min. appeared min intensity initially growing fast slowing down 15 produce sigmoidal profile.59Colacino Carta Pia Porcheddu Ricci P.C. Processing kinetics.ACS Omega. 3: 9196-9209Crossref (46) found be complete 25 min, coinciding disappearance 1 1B). pattern sample showed accordance S15).9Ding Scholar,60Shiraki Kim Nakashima Room-temperature enhanced area nitrogen-doped graphite 44: 1488-1490Crossref Next, TbBd-COF61Daugherty M.C. Improved ?-ketoenamine-linked monomer exchange reactions.Chem. 55: 2680-2683Crossref benzidine (Bd), extended linear diamine linker, Tb. TbBd-COF conducted (1:1, 6 M (? 0.61 ?L/mg). As COF-LZU1, proceeds (2), corresponding signals 2.6°, 2.9°, 3.0°, 3.2°, 3.8° TbBd-COF. barely few minutes appearing 4 significantly slower comparison likely lower reactivity linker compared pPDA. started appear initial induction those persisting 1B 1E). milled shows successful S15).61Daugherty third series C3-C2 IISERP-COF4,62Gomes Bhanja Bhaumik triazine-based polymer CO 2 adsorption.Chem. 10050-10053Crossref obtained 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAT) terephthaladehyde (BDA) additives 0.94 ?L/mg) 1C). No observed case IISERP-COF4 1C S13A). Notably, second 110 S9A). starts period steep rate, 40 time. Full consumption TAT achieved around Measured literature S15).62Gomes monitored N-COF63Wang Xu Exceptional iodine capture frameworks.Adv. 30e1801991Crossref (203) two components t