Precise recognition of palladium through interlaminar chelation in a covalent organic framework

•An interlayer synergistic binding mode for Pd recognition is achieved in a COF•COF-TzDa shows ultrahigh uptake selectivity and capacity toward Pd•One-round enrichment purification of from the nuclear waste realized Separation palladium isotopes used fuel high significance but faces notable challenges, due to harsh reprocessing condition with combined acidity, strong radiation, vast interfering ions. Compared proposed solvent extraction method, where extractants suffer limited stability efficiency, covalent organic frameworks are shown as new generation solid extractant not only because their elevated acids resistance radiations also they exhibit distinct mode, markedly deviating chelation within single ligand molecule, notably enhanced extraction. This leads previously unachieved one-round simulated high-level solution. strategy, general, opens avenue remedy various types pollutants extract many strategic resources complex conditions. Palladium fission products represent precious alternative besides its natural reserves therefore have value. The practical use currently challenging, originating separation under Herein, we present an metal-recognition manner molecule extraction, selective framework. experimental, structural, theoretical analyses corroborate that enol-to-keto tautomerization Pd2+ instead other undesired metal ions, two oxygen donors adjacent layers free nitrate ions work together planar tetracoordination model. Fast adsorption kinetics, capacity, solution unprecedentedly dynamic breakthrough experiment. As one light platinum group metals (PGMs), (Pd) plays vital role automotive industries convert noxious emissions harmless products, electronic sectors produce circuit boards, fine chemicals manufacture vitamins, antibiotics, others.1Gunn G. Critical Metals Handbook. First Edition. John Wiley & Sons, Ltd., 2014: 284-311Google Scholar However, abundance Earth′s crust extremely low, at 0.1∼3 ng g−1.2Rao C.R.M. Reddi G.S. Platinum (PGM); occurrence, recent trends determination.TrAC Trends Anal. Chem. 2000; 19: 565-586Crossref Scopus (271) Google conventional refining process minerals requires numerous recycling intermediate steps, giving rise tedious labor-intensive operations.3Nikoloski A.N. Ang K.-L. Review application ion exchange resins recovery platinum-group From hydrochloric acid solutions.Mineral Processing Extractive Metallurgy Review. 2013; 35: 369-389Crossref (113) Considering low process, (UNF) regarded promising approach obtain large amount Pd.4Zha M. Liu J. Wong Y.-L. Xu Z. Extraction waste-like acidic solutions by metal–organic framework sulfur alkene functions.J. Mater. A. 2015; 3: 3928-3934Crossref It was predicted accumulated UNF will increase up 1,000 tons 2030, making 11% total proven recoverable reserves.5Xu Zhang Q. Lv Y. Wang S. Simultaneous noble Cs highly radioactive borosilicate glass using liquid tin reductive heat treatment.Mater. Phys. 2020; 246: 122856Crossref (3) Solvent commonly accepted method UNF.6Ruhela R. Singh A.K. Tomar B.S. Hubli R.C. level - review.RSC Adv. 2014; 4: 24344-24350Crossref (50) propensity decompose extreme conditions radioactivity, temperature. In addition, chemical composition complicated since more than 40 elements 1,500 nuclides fresh 235U.7Ozawa Suzuki Takeshita K. Advanced hydrometallurgical actinides rare cycle.Solvent Extr. Res. Dev. Jpn. 2010; 17: 19-34Crossref (13) coexisting especially Ni, Cd, Ag similar properties Pd, decrease efficiency. daunting challenge achieve capability, considering integration sufficient stability, selectivity, solubility extractant. Experiences highlight important preorganized improving ligand.8Leoncini Huskens Verboom W. Ligands f-element cycle.Chem. Soc. Rev. 2017; 46: 7229-7273Crossref PubMed origin this preorganization strategy stems specific complexation proteins multiple rationally organized perfectly adapt guest configuration, achieving affinity selectivity.9Fasting C. Schalley C.A. Weber Seitz O. Hecht Koksch B. Dernedde Graf Knapp E.W. Haag Multivalency organization action principle.Angew. Int. Ed. Engl. 2012; 51: 10472-10498Crossref (758) Such idea design be strictly embedded certain spatial positions so match coordination preference desired ions.10Mei L. Ren P. Wu Q.-Y. Ke Y.B. Geng J.-S. Xing X.-Q. Huang Z.-W. Hu K.-Q. et al.Actinide inspired self-assembled metal-polyphenolic nanocages.J. Am. 142: 16538-16545Crossref (39) Various been developed separation, such malonamides, diglycolamides, carbamoyl methylphosphine oxides.6Ruhela These featured flexible ligands connected via carbon chains higher degree rotation freedom tolerable. allows multidentate chelate possible, on side, lowers these can themselves A useful way restrict intramolecular applies extended conjugation structural rigidity. Picoliamides salicylaldimines examples avails separation.11Liu T.-M. Lin K.-T. Li F.-J. Lee G.-H. Chen M.-C. Lai C.K. π–π interactions metallomesogens.Tetrahedron. 71: 8649-8660Crossref (9) Scholar, 12Oncel N. Kasumov V.T. Sahin E. Ulusoy Synthesis, characterization catalytic activity bis(N-2,6-diphenylphenol-R-salicylaldiminato)Pd(II) complexes Suzuki-Miyaura CO2 fixation reactions.J. Organomet. 2016; 811: 81-90Crossref (11) 13Alyapyshev M.Y. Babain V.A. Tkachenko L.I. Eliseev I.I. Didenko A.V. Petrov M.L. Dependence 2,6-Dicarboxypyridine diamides structure.Solvent Ion Exch. 2011; 29: 619-636Crossref (70) should noted there cases poorer performance compared analogs consequence inappropriate positioning donors,14Yamada Rajiv Gandhi Sato D. Kaneta Kimura Comparative study palladium(II) thioamide-modified acyclic cyclic extractants.Ind. Eng. 55: 8914-8921Crossref (20) indicating accuracy required great faced designing rigid extractants. protein event, lesson Nature, provides hints how utilize noncovalent reach semirigid state anchored near ideal position α/β folds or hydrogen bonds enjoy adjust configuration small extent.15Zhou Bosscher Ozçubukçu C.J. Jensen M.P. He engineered bind uranyl selectively femtomolar affinity.Nat. 6: 236-241Crossref (235) Scholar,16Yu Yuan Feng T. Sun Spidroin-inspired, High-Strength, loofah-shaped fiber capturing uranium seawater.Angew. 59: 15997-16001Crossref (43) Thus, possess places metal-preferred local structure terms self-adaption. Along guidance, two-dimensional (2D COFs)17Liu Tan K.T. Gong Xie Lu Yang H. Jiang Covalent frameworks: platform ordered materials advanced applications.Chem. 2021; 50: 120-242Crossref 18Guan X. Ma Xue Fang Yan Valtchev V. Qiu Chemically stable polyarylether-based frameworks.Nat. 2019; 11: 587-594Crossref (376) 19Wang 49: 708-735Crossref 20Liu Z.P. P.L. Ding S.Y. Pyrimidazole-based integrating functionality ultrastability isocyanide chemistry.J. 20956-20961Crossref (37) 21Zhao Sui Chang Liang trifluoromethyl-grafted ultra-stable fluorescent detection pesticides.J. 8: 25156-25164Crossref strike us spacing appropriate coordination,22Ding Gao Song W.G. Su C.Y. Construction catalysis: Pd/COF-LZU1 coupling reaction.J. 133: 19816-19822Crossref (1669) Scholar,23Kaleeswaran Antony Sharma Malani Murugavel Catalysis capture palladium-incorporated frameworks.ChemPlusChem. 82: 1253-1265Crossref (40) which envisioned access. Different common strategies through confined channel effect,24He Dong Dai Pan nitrogen-rich simultaneous iodine methyl iodide.Chem. 7: 699-714Abstract Full Text PDF (110) Scholar,25Chang Zhao Guan Yu Tetrathiafulvalene-based capture.Chem. Sci. 12: 8452-8457Crossref ionic COFs,26He F. Zhou al.Mechanism unravelling ultrafast 99TcO4- radiation-resistant cationic framework: radiological experiment molecular dynamics simulation study.Chem. 10: 4293-4305Crossref 27Ma Y.-G. H.-Q. Zang H.-Y. Zhu Cationic simple anionic porosity tuning proton conduction.J. 138: 5897-5903Crossref (504) 28Wang Lan Peng Chai Gibson J.K. Zhai Shi Radiation controllable synthesis robust conjugates efficient column 99TcO4−.Chem. 2796-2809Abstract (72) pore wall modification (Figure 1A),29Xu Stable, crystalline, porous, chiral organocatalysts.Nat. 905-912Crossref (973) 30Sun Aguila Perman Earl L.D. Abney C.W. Cheng Wei Nguyen Wojtas Postsynthetically modified effective mercury removal.J. 139: 2786-2793Crossref (673) 31Yu Zheng Tao al.Phosphonate-decorated actinide extraction: Under conditions.CCS 1: 286-295Google 32Zhang C.-R. Cui W.-R. R.-H. X.-R. Y.-D. R.-P. J.-D. Alkynyl-based sp2 carbon-conjugated seawater photoinduced effects.CCS 168-179Crossref (35) synergetic 2D COFs takes advantage unperceived π-π stacking, interaction permits donor orientation position. endows flexibility same time. More importantly, most ∼3.5 Å interlaminar distance,33Li Guo Laminated self-standing membrane uniformly distributed subnanopores sieving.Nat. Commun. 599Crossref (163) Scholar,34Chen Silver M.A. Gui Diwu al.Covalent functionalized 8-hydroxyquinoline dual-mode colorimetric pH sensor.ACS Appl. Interfaces. 2018; 15364-15368Crossref quadridentate complexes.11Liu Following idea, constructed salicylaldimine-based COF (COF-TzDa)35Qian H.-L. C.-X. X.-P. High-crystallinity dual fluorescence ratiometric sensing application.ACS 9: 24999-25005Crossref (165) 36Zhi Shao Xia Mu efficient, metal-free, heterogeneous organocatalysts mild conditions.J. 374-382Crossref 37Liu Qian Room-temperature preparation amino enantiomers.RSC 15383-15386Crossref 38Mu Qin Two-dimensional imine-linked oxidation olefins.ACS 22856-22863Crossref (106) 39Sahabudeen Qi Ballabio Položij Olthof Shivhare Jing Park al.Highly crystalline semiconducting imine-based polymers enabled interfacial synthesis.Angew. 6028-6036Crossref (67) 40Sun Cao Interfacial amino-functionalized nanotubes electrochemical performance.Chem. (Camb). 53: 6303-6306Crossref 41Xu Tang Pyrolysis general template converting skeletons into conducting microporous carbons high-performance energy storage.Chem. 11690-11693Crossref 42Hao Wan L.J. Confined thin films superspreading water layer.J. 140: 12152-12158Crossref (176) proof concept recognition. COF-TzDa indeed touches our expectation much intralayer coordination, contributes maximum (265.4 mg g−1) close value (290.5 g−1). Our has demonstrated reasonability feasibility interlayered deriving coupled self-adaptive fragments adsorbents. synthesized solvothermal condensation 4,4′,4′′-(1,3,5-triazine-2,4,6-triyl)trianiline (Tz) 2,5-dihydroxyterephthalaldehyde (Da) mixed o-dichlorobenzene (o-DCB)/n-butanol (3/1, v/v) 120°C 72 h yielding crimson crystallites (Scheme S1). characterized powder X-ray diffraction (PXRD) analysis. Figures 1B S1, measured PXRD pattern exhibits several dominant intense peaks 2.69°, 4.77°, 5.50°, 7.37°, 9.73°, assigned [100], [110], [200], [210], [220] Bragg planes, respectively.38Mu broad peak 26.01° observed, corresponding stacking COF. indicates possesses preferably serrated AA-stacking arrangement 1C). We model shifting neighboring approximately 1.422 respect each (see details CIF), partially minimizes repulsion between layers. Therefore, form energetically adopted AA-eclipsed structures.43Lukose Kuc Frenzel Heine On reticular construction frameworks.Beilstein Nanotechnol. 60-70Crossref (123) Scholar,44Lukose layered covalent-organic frameworks.Chemistry. 2388-2392Crossref (168) After Pawley refinement, refined profile matches well experimental (Rwp = 8.41%, Rp 6.54%), simulation. unit cell parameters b 36.85 Å, c 10.28 α β 90°, γ 120° space P31. Figure 1, distance atoms 3.67 slightly longer opposite nitrogen (2.76 Å) well-defined square-planar complex.45Sarto L.E. Badaró W.P.D. de Gois E.P. Barbosa M.I.F. Torres Viana R.B. Honorato Castellano E.E. Almeida E.T. Crystal structures DFT analysis Schiff bases derived N,N-dialkyl-p-phenylenediamines.J. Mol. Struct. 1204: 127549Crossref Despite this, adjustable interaction, well-arranged sites neighbor suggest capture. product further Fourier transform infrared (FTIR) spectra S2). reaction, some characteristic disappear stretching vibrational aldehyde 1,663 cm−1 3,300∼3,500 cm−1. meantime, appearance band C=N 1,579 successful formation Schiff-base.38Mu porous nature verified type-IV adsorption-desorption isotherm S3). surface area (SBET) determined 1,426 m2 g−1 after activation supercritical CO2.37Liu Thermogravimetric (TGA) maintains weight until 375°C S4). To judge COF-TzDa, immersed pristine samples 2, 3 M HNO3 12 h, respectively. treating 2 HNO3, intensity profiles sharply decreases, obvious damage well-ordered S5). contrary, sample displays as-synthesized soaking 1 HNO3. Brunauer-Emmett-Teller (BET) decreases 876 g−1, may attributed protonation imine groups partial slipping.46Kandambeth Venkatesh Shinde D.B. Kumari Halder Verma Banerjee Self-templated chemically hollow spherical framework.Nat. 6786Crossref (382) moderate ascribed bond formed hydroxyl groups, enhancing planarity skeleton layers.47Halder Kandambeth Biswal B.P. Kaur Roy N.C. Addicoat Salunke Vanka al.Decoding morphological diversity dimensional core modulation.Angew. 7806-7810Crossref (122) characterizations investigated Due tolerance HLLW medium, first kinetics nitric stirring mixture 30 mL contact time.48Fei Oliver S.R.J. Copper hydroxide Ethanedisulfonate: inorganic material high-capacity anion exchange.Angew. 9066-9070Crossref (54) Scholar,49Soe Ehlke silver pyrazine polymer water.Environ. Technol. 7663-7672Crossref (24) immersing solution, color immediately changes reddish orange dark brown. beginning min, remaining concentration dramatically 102.01 13.60 L−1, it finally reaches equilibrium 120 min removal percentage 99.8% 2A). fast sorption accessible well-organized COF-TzDa. line pseudo-second-order kinetic (Table S1), captures chemisorption (Figures S6 S7).50Chen Bai Cai al.Ultrafast amidoxime appended metal-organic framework.ACS 32446-32451Crossref (218) acquire carried out initial concentrations ranging 69.09 481.97 L−1. worth noting 265.4 2B), 290.5 cooperative atoms. Even though adsorbents excellent relatively weak S2),51Chen Weng Selective Pd(II) pyridine-functionalized graphene oxide prepared radiation-induced grafting polymerization reduction.ACS 24560-24570Crossref 52Daliran Ghazagh-Miri Oveisi A.R. Khajeh Navalón Âlvaro Ghaffari-Moghaddam Samareh Delarami García pyridyltriazol zirconium palladium.ACS 25221-25232Crossref (75) 53Zhang Luo Pei Specific transfer PdCl42− [X-Pd-Y] 3D ion-imprinted footprint cavity.Chem. 405: 126613Crossref case remove aid confirm speculation, capacities isomorphic replacing triazine phenyl S8).46Kandambeth shaking 0.1 107.83 L−1 were 107.77 107.57 analog COF-OH S2), respectively, preliminarily confirms mainly occurring salicylaldimine site prove availability examined different 0.2 experiments all around 269.71 based four parallel trials, suggests robustness 2C). radioactivity radiation doses β-ray 200 kGy. irradiation, patterns almost no one, S9). 2D, irradiated one. reutilization application. selected thiourea desorption agent well-known ions.54Ning Rh, Ru silica-based IsoBu-BTP/SiO2-P adsorbent.Hydrometallurgy. 191: 105207Crossref (26) cycles, slowly 236.06 198.06 2E). slight reduction generating mildly incomplete d