Heterogeneous catalysis based on supramolecular association

[EN] Heterogeneous catalysis is based mostly on materials built with strong covalent bonds. However, supramolecular aggregation in which individual components self-assemble due to non-covalent interactions to create a larger entity offers also considerable potential for the preparation of materials with application in catalysis. The present article provides a perspective on the use of supramolecular aggregation for the development of heterogeneous catalysts. One of the main advantages of this approach is that the preparation procedure based on spontaneous self-assembly is frequently simpler than those that require the formation of covalent bonds. The emphasis in this article has been placed on the use in the preparation of heterogeneous catalysts of not only carbon materials, particularly graphene and carbon nanotubes, but also dendrimers and organic capsules. Examples of hybrid organic-inorganic materials such as mesoporous organosilicas, metal-organic frameworks and heteropolyacids are also briefly described. The purpose is to illustrate the breadth of the field and the diverse array of possibilities already developed to apply the concepts of supramolecular association in heterogeneous catalysis.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa and CTQ2015-69153-CO2-R1) and Generalitat Valenciana (Prometeo 2017-083) is gratefully acknowledged. Prof Parvulescu thanks UEFISCDI for the Projects 121/2017 and 32PCCD1/2018.Parvulescu, VI.; García Gómez, H. (2018). Heterogeneous catalysis based on supramolecular association. Catalysis Science & Technology. 8(19):4834-4857. https://doi.org/10.1039/c8cy01295d48344857819J.-M. Lehn , Supramolecular chemistry , Vch , Weinheim , 1995J. W. Steed , J. L.Atwood and P. A.Gale , Definition and emergence of supramolecular chemistry , Wiley Online Library , 2012Herbst, S., Soberats, B., Leowanawat, P., Stolte, M., Lehmann, M., & Würthner, F. (2018). Self-assembly of multi-stranded perylene dye J-aggregates in columnar liquid-crystalline phases. Nature Communications, 9(1). doi:10.1038/s41467-018-05018-6Würthner, F., Thalacker, C., & Sautter, A. (1999). Hierarchical Organization of Functional Perylene Chromophores to Mesoscopic Superstructures by Hydrogen Bonding and π-π Interactions. Advanced Materials, 11(9), 754-758. doi:10.1002/(sici)1521-4095(199906)11:93.0.co;2-5JELLEY, E. E. (1936). Spectral Absorption and Fluorescence of Dyes in the Molecular State. Nature, 138(3502), 1009-1010. doi:10.1038/1381009a0Wang, J., Liu, D., Zhu, Y., Zhou, S., & Guan, S. (2018). Supramolecular packing dominant photocatalytic oxidation and anticancer performance of PDI. Applied Catalysis B: Environmental, 231, 251-261. doi:10.1016/j.apcatb.2018.03.026Liebing, P., Pietrasiak, E., Otth, E., Kalim, J., Bornemann, D., & Togni, A. (2018). Supramolecular Aggregation of Perfluoroorganyl Iodane Reagents in the Solid State and in Solution. European Journal of Organic Chemistry, 2018(27-28), 3771-3781. doi:10.1002/ejoc.201800358Zhang, S. (2003). Fabrication of novel biomaterials through molecular self-assembly. Nature Biotechnology, 21(10), 1171-1178. doi:10.1038/nbt874Balzani, V., Gómez-López, M., & Stoddart, J. F. (1998). Molecular Machines. Accounts of Chemical Research, 31(7), 405-414. doi:10.1021/ar970340yBai, C., & Liu, M. (2012). Implantation of nanomaterials and nanostructures on surface and their applications. Nano Today, 7(4), 258-281. doi:10.1016/j.nantod.2012.05.002Lehn, J.-M. (2002). Toward complex matter: Supramolecular chemistry and self-organization. Proceedings of the National Academy of Sciences, 99(8), 4763-4768. doi:10.1073/pnas.072065599Lehn, J.-M. (2007). From supramolecular chemistry towards constitutional dynamic chemistry and adaptive chemistry. Chem. Soc. Rev., 36(2), 151-160. doi:10.1039/b616752gSanders, J. K. M. (1998). Supramolecular Catalysis in Transition. Chemistry - A European Journal, 4(8), 1378-1383. doi:10.1002/(sici)1521-3765(19980807)4:83.0.co;2-3A. Lützen , Supramolecular Catalysis , ed. P. W. N. M. van Leeuwen , Wiley Online Library , 2008Zhao, L., Sui, X.-L., Li, J.-Z., Zhang, J.-J., Zhang, L.-M., Huang, G.-S., & Wang, Z.-B. (2018). Supramolecular assembly promoted synthesis of three-dimensional nitrogen doped graphene frameworks as efficient electrocatalyst for oxygen reduction reaction and methanol electrooxidation. Applied Catalysis B: Environmental, 231, 224-233. doi:10.1016/j.apcatb.2018.03.020Wang, X., Liu, Q., Yang, Q., Zhang, Z., & Fang, X. (2018). Three-dimensional g-C3N4 aggregates of hollow bubbles with high photocatalytic degradation of tetracycline. Carbon, 136, 103-112. doi:10.1016/j.carbon.2018.04.059Yao, Y., Wei, X., Cai, Y., Kong, X., Chen, J., Wu, J., & Shi, Y. (2018). Hybrid supramolecular materials constructed from pillar[5]arene based host–guest interactions with photo and redox tunable properties. Journal of Colloid and Interface Science, 525, 48-53. doi:10.1016/j.jcis.2018.04.034Leung, F. C.-M., Leung, S. Y.-L., Chung, C. Y.-S., & Yam, V. W.-W. (2016). Metal–Metal and π–π Interactions Directed End-to-End Assembly of Gold Nanorods. Journal of the American Chemical Society, 138(9), 2989-2992. doi:10.1021/jacs.6b01382Lu, C., Zhang, M., Tang, D., Yan, X., Zhang, Z., Zhou, Z., … Stang, P. J. (2018). Fluorescent Metallacage-Core Supramolecular Polymer Gel Formed by Orthogonal Metal Coordination and Host–Guest Interactions. Journal of the American Chemical Society, 140(24), 7674-7680. doi:10.1021/jacs.8b03781Sun, Y., Li, S., Zhou, Z., Saha, M. L., Datta, S., Zhang, M., … Stang, P. J. (2017). Alanine-Based Chiral Metallogels via Supramolecular Coordination Complex Platforms: Metallogelation Induced Chirality Transfer. Journal of the American Chemical Society, 140(9), 3257-3263. doi:10.1021/jacs.7b10769Du, P., Jaouen, M., Bocheux, A., Bourgogne, C., Han, Z., Bouchiat, V., … Attias, A.-J. (2014). Surface-Confined Self-Assembled Janus Tectons: A Versatile Platform towards the Noncovalent Functionalization of Graphene. Angewandte Chemie, 126(38), 10224-10230. doi:10.1002/ange.201403572Georgakilas, V., Otyepka, M., Bourlinos, A. B., Chandra, V., Kim, N., Kemp, K. C., … Kim, K. S. (2012). Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications. Chemical Reviews, 112(11), 6156-6214. doi:10.1021/cr3000412Qu, S., Li, M., Xie, L., Huang, X., Yang, J., Wang, N., & Yang, S. (2013). Noncovalent Functionalization of Graphene Attaching [6,6]-Phenyl-C61-butyric Acid Methyl Ester (PCBM) and Application as Electron Extraction Layer of Polymer Solar Cells. ACS Nano, 7(5), 4070-4081. doi:10.1021/nn4001963Du, P., Bléger, D., Charra, F., Bouchiat, V., Kreher, D., Mathevet, F., & Attias, A.-J. (2015). A versatile strategy towards non-covalent functionalization of graphene by surface-confined supramolecular self-assembly of Janus tectons. Beilstein Journal of Nanotechnology, 6, 632-639. doi:10.3762/bjnano.6.64Chefetz, B., Deshmukh, A. P., Hatcher, P. G., & Guthrie, E. A. (2000). Pyrene Sorption by Natural Organic Matter. Environmental Science & Technology, 34(14), 2925-2930. doi:10.1021/es9912877Pan, B., & Xing, B. (2008). Adsorption Mechanisms of Organic Chemicals on Carbon Nanotubes. Environmental Science & Technology, 42(24), 9005-9013. doi:10.1021/es801777nChen, J., Chen, W., & Zhu, D. (2008). Adsorption of Nonionic Aromatic Compounds to Single-Walled Carbon Nanotubes: Effects of Aqueous Solution Chemistry. Environmental Science & Technology, 42(19), 7225-7230. doi:10.1021/es801412jPodeszwa, R. (2010). Interactions of graphene sheets deduced from properties of polycyclic aromatic hydrocarbons. The Journal of Chemical Physics, 132(4), 044704. doi:10.1063/1.3300064Peris, E. (2016). Polyaromatic N-heterocyclic carbene ligands and π-stacking. Catalytic consequences. Chemical Communications, 52(34), 5777-5787. doi:10.1039/c6cc02017hRuiz-Botella, S., & Peris, E. (2015). Unveiling the Importance of π-Stacking in Borrowing-Hydrogen Processes Catalysed by Iridium Complexes with Pyrene Tags. Chemistry - A European Journal, 21(43), 15263-15271. doi:10.1002/chem.201502948Sabater, S., Mata, J. A., & Peris, E. (2014). Immobilization of Pyrene-Tagged Palladium and Ruthenium Complexes onto Reduced Graphene Oxide: An Efficient and Highly Recyclable Catalyst for Hydrodefluorination. Organometallics, 34(7), 1186-1190. doi:10.1021/om501040xSabater, S., Mata, J. A., & Peris, E. (2014). Catalyst Enhancement and Recyclability by Immobilization of Metal Complexes onto Graphene Surface by Noncovalent Interactions. ACS Catalysis, 4(6), 2038-2047. doi:10.1021/cs5003959Wittmann, S., Schätz, A., Grass, R. N., Stark, W. J., & Reiser, O. (2010). A Recyclable Nanoparticle-Supported Palladium Catalyst for the Hydroxycarbonylation of Aryl Halides in Water. Angewandte Chemie International Edition, 49(10), 1867-1870. doi:10.1002/anie.200906166Keller, M., Collière, V., Reiser, O., Caminade, A.-M., Majoral, J.-P., & Ouali, A. (2013). Pyrene-Tagged Dendritic Catalysts Noncovalently Grafted onto Magnetic Co/C Nanoparticles: An Efficient and Recyclable System for Drug Synthesis. Angewandte Chemie International Edition, 52(13), 3626-3629. doi:10.1002/anie.201209969MISHRA, S., ARORA, S., NAGPAL, R., & SINGH CHAUHAN, S. M. (2014). Sulfonated graphenes catalyzed synthesis of expanded porphyrins and their supramolecular interactions with pristine graphene. Journal of Chemical Sciences, 126(6), 1729-1736. doi:10.1007/s12039-014-0731-8Xing, L., Xie, J.-H., Chen, Y.-S., Wang, L.-X., & Zhou, Q.-L. (2008). Simply Modified Chiral Diphosphine: Catalyst Recyclingvia Non-covalent Absorption on Carbon Nanotubes. Advanced Synthesis & Catalysis, 350(7-8), 1013-1016. doi:10.1002/adsc.200700617Che, G., Lakshmi, B. B., Fisher, E. R., & Martin, C. R. (1998). Carbon nanotubule membranes for electrochemical energy storage and production. Nature, 393(6683), 346-349. doi:10.1038/30694Zhu, Z., Su, D., Weinberg, G., & Schlögl, R. (2004). Supermolecular Self-Assembly of Graphene Sheets: Formation of Tube-in-Tube Nanostructures. Nano Letters, 4(11), 2255-2259. doi:10.1021/nl048794tFukushima, T. (2003). Molecular Ordering of Organic Molten Salts Triggered by Single-Walled Carbon Nanotubes. Science, 300(5628), 2072-2074. doi:10.1126/science.1082289Tunckol, M., Durand, J., & Serp, P. (2012). Carbon nanomaterial–ionic liquid hybrids. Carbon, 50(12), 4303-4334. doi:10.1016/j.carbon.2012.05.017Subramaniam, K., Das, A., & Heinrich, G. (2011). Development of conducting polychloroprene rubber using imidazolium based ionic liquid modified multi-walled carbon nanotubes. Composites Science and Technology, 71(11), 1441-1449. doi:10.1016/j.compscitech.2011.05.018Chu, H., Shen, Y., Lin, L., Qin, X., Feng, G., Lin, Z., … Li, Y. (2010). Ionic-Liquid-Assisted Preparation of Carbon Nanotube-Supported Uniform Noble Metal Nanoparticles and Their Enhanced Catalytic Performance. Advanced Functional Materials, 20(21), 3747-3752. doi:10.1002/adfm.201001240Chun, Y. S., Shin, J. Y., Song, C. E., & Lee, S. (2008). Palladium nanoparticles supported onto ionic carbon nanotubes as robust recyclable catalysts in an ionic liquid. Chem. Commun., (8), 942-944. doi:10.1039/b715463aSalvo, A. M. P., La Parola, V., Liotta, L. F., Giacalone, F., & Gruttadauria, M. (2016). Highly Loaded Multi-Walled Carbon Nanotubes Non-Covalently Modified with a Bis-Imidazolium Salt and their Use as Catalyst Supports. ChemPlusChem, 81(5), 471-476. doi:10.1002/cplu.201600023Park, H. S., Choi, B. G., Yang, S. H., Shin, W. H., Kang, J. K., Jung, D., & Hong, W. H. (2009). Ionic-Liquid-Assisted Sonochemical Synthesis of Carbon-Nanotube-Based Nanohybrids: Control in the Structures and Interfacial Characteristics. Small, 5(15), 1754-1760. doi:10.1002/smll.200900128Noël, S., Léger, B., Ponchel, A., Philippot, K., Denicourt-Nowicki, A., Roucoux, A., & Monflier, E. (2014). Cyclodextrin-based systems for the stabilization of metallic(0) nanoparticles and their versatile applications in catalysis. Catalysis Today, 235, 20-32. doi:10.1016/j.cattod.2014.03.030Wyrwalski, F., Léger, B., Lancelot, C., Roucoux, A., Monflier, E., & Ponchel, A. (2011). Chemically modified cyclodextrins as supramolecular tools to generate carbon-supported ruthenium nanoparticles: An application towards gas phase hydrogenation. Applied Catalysis A: General, 391(1-2), 334-341. doi:10.1016/j.apcata.2010.07.006Jean-Marie, A., Griboval-Constant, A., Khodakov, A. Y., Monflier, E., & Diehl, F. (2011). β-Cyclodextrin for design of alumina supported cobalt catalysts efficient in Fischer–Tropsch synthesis. Chemical Communications, 47(38), 10767. doi:10.1039/c1cc13800fLéger, B., Menuel, S., Ponchel, A., Hapiot, F., & Monflier, E. (2012). Nanoparticle-Based Catalysis using Supramolecular Hydrogels. Advanced Synthesis & Catalysis, 354(7), 1269-1272. doi:10.1002/adsc.201100888Zhang, J.-J., Ge, J.-M., Wang, H.-H., Wei, X., Li, X.-H., & Chen, J.-S. (2016). Activating Oxygen Molecules over Carbonyl-Modified Graphitic Carbon Nitride: Merging Supramolecular Oxidation with Photocatalysis in a Metal-Free Catalyst for Oxidative Coupling of Amines into Imines. ChemCatChem, 8(22), 3441-3445. doi:10.1002/cctc.201601065Qi, W., Liu, W., Liu, S., Zhang, B., Gu, X., Guo, X., & Su, D. (2014). Heteropoly Acid/Carbon Nanotube Hybrid Materials as Efficient Solid-Acid Catalysts. ChemCatChem, 6(9), 2613-2620. doi:10.1002/cctc.201402270Willner, B., Katz, E., & Willner, I. (2006). Electrical contacting of redox proteins by nanotechnological means. Current Opinion in Biotechnology, 17(6), 589-596. doi:10.1016/j.copbio.2006.10.008Smalley, R. E., Li, Y., Moore, V. C., Price, B. K., Colorado, R., Schmidt, H. K., … Tour, J. M. (2006). Single Wall Carbon Nanotube Amplification: En Route to a Type-Specific Growth Mechanism. Journal of the American Chemical Society, 128(49), 15824-15829. doi:10.1021/ja065767rJasti, R., Bhattacharjee, J., Neaton, J. B., & Bertozzi, C. R. (2008). Synthesis, Characterization, and Theory of [9]-, [12]-, and [18]Cycloparaphenylene: Carbon Nanohoop Structures. Journal of the American Chemical Society, 130(52), 17646-17647. doi:10.1021/ja807126uFort, E. H., Donovan, P. M., & Scott, L. T. (2009). Diels−Alder Reactivity of Polycyclic Aromatic Hydrocarbon Bay Regions: Implications for Metal-Free Growth of Single-Chirality Carbon Nanotubes. Journal of the American Chemical Society, 131(44), 16006-16007. doi:10.1021/ja907802gFort, E. H., & Scott, L. T. (2010). One-Step Conversion of Aromatic Hydrocarbon Bay Regions into Unsubstituted Benzene Rings: A Reagent for the Low-Temperature, Metal-Free Growth of Single-Chirality Carbon Nanotubes. Angewandte Chemie, 122(37), 6776-6778. doi:10.1002/ange.201002859Lu, D., Cui, S., & Du, P. (2017). Large π-Extension of Carbon Nanorings by Incorporating Hexa-peri-hexabenzocoronenes. Synlett, 28(14), 1671-1677. doi:10.1055/s-0036-1588830Niu, T., Wu, J., Ling, F., Jin, S., Lu, G., & Zhou, M. (2017). Halogen-Adatom Mediated Phase Transition of Two-Dimensional Molecular Self-Assembly on a Metal Surface. Langmuir, 34(1), 553-560. doi:10.1021/acs.langmuir.7b03796Lee, J. W., Samal, S., Selvapalam, N., Kim, H.-J., & Kim, K. (2003). Cucurbituril Homologues and Derivatives: New Opportunities in Supramolecular Chemistry. Accounts of Chemical Research, 36(8), 621-630. doi:10.1021/ar020254kNi, X.-L., Xiao, X., Cong, H., Zhu, Q.-J., Xue, S.-F., & Tao, Z. (2014). Self-Assemblies Based on the «Outer-Surface Interactions» of Cucurbit[n]urils: New Opportunities for Supramolecular Architectures and Materials. Accounts of Chemical Research, 47(4), 1386-1395. doi:10.1021/ar5000133Wang, P., Wu, Y., Zhao, Y., Yu, Y., Zhang, M., & Cao, L. (2017). Crystalline nanotubular framework constructed by cucurbit[8]uril for selective CO2 adsorption. Chemical Communications, 53(40), 5503-5506. doi:10.1039/c7cc02074kJames, S. L. (2003). Metal-organic frameworks. Chemical Society Reviews, 32(5), 276. doi:10.1039/b200393gH.-C. Zhou , J. R.Long and O. M.Yaghi , Introduction to metal–organic frameworks , ACS Publications , 2012Dhakshinamoorthy, A., Asiri, A. M., & Garcia, H. (2017). Metal Organic Frameworks as Versatile Hosts of Au Nanoparticles in Heterogeneous Catalysis. ACS Catalysis, 7(4), 2896-2919. doi:10.1021/acscatal.6b03386Dhakshinamoorthy, A., & Garcia, H. (2014). Cascade Reactions Catalyzed by Metal Organic Frameworks. ChemSusChem, 7(9), 2392-2410. doi:10.1002/cssc.201402148Dhakshinamoorthy, A., Asiri, A. M., & Garcia, H. (2014). Catalysis by metal–organic frameworks in water. Chem. Commun., 50(85), 12800-12814. doi:10.1039/c4cc04387aDhakshinamoorthy, A., Asiri, A. M., & Garcia, H. (2016). Metal-Organic Frameworks as Catalysts for Oxidation Reactions. Chemistry - A European Journal, 22(24), 8012-8024. doi:10.1002/chem.201505141Noh, T. H., & Jung, O.-S. (2016). Recent Advances in Various Metal–Organic Channels for Photochemistry beyond Confined Spaces. Accounts of Chemical Research, 49(9), 1835-1843. doi:10.1021/acs.accounts.6b00291Tabacchi, G. (2018). Supramolecular Organization in Confined Nanospaces. ChemPhysChem, 19(11), 1249-1297. doi:10.1002/cphc.201701090Haldar, R., Reddy, S. K., Suresh, V. M., Mohapatra, S., Balasubramanian, S., & Maji, T. K. (2014). Flexible and Rigid Amine-Functionalized Microporous Frameworks Based on Different Secondary Building Units: Supramolecular Isomerism, Selective CO2Capture, and Catalysis. Chemistry - A European Journal, 20(15), 4347-4356. doi:10.1002/chem.201303610Tan, L.-L., Song, N., Zhang, S. X.-A., Li, H., Wang, B., & Yang, Y.-W. (2016). Ca2+, pH and thermo triple-responsive mechanized Zr-based MOFs for on-command drug release in bone diseases. Journal of Materials Chemistry B, 4(1), 135-140. doi:10.1039/c5tb01789kRimoldi, M., Howarth, A. J., DeStefano, M. R., Lin, L., Goswami, S., Li, P., … Farha, O. K. (2016). Catalytic Zirconium/Hafnium-Based Metal–Organic Frameworks. ACS Catalysis, 7(2), 997-1014. doi:10.1021/acscatal.6b02923Winter, A., Hager, M. D., Newkome, G. R., & Schubert, U. S. (2011). The Marriage of Terpyridines and Inorganic Nanoparticles: Synthetic Aspects, Characterization Techniques, and Potential Applications. Advanced Materials, 23(48), 5728-5748. doi:10.1002/adma.201103612Ding, X., Gao, Y., Ye, L., Zhang, L., & Sun, L. (2015). Assembling Supramolecular Dye-Sensitized Photoelectrochemical Cells for Water Splitting. ChemSusChem, 8(23), 3992-3995. doi:10.1002/cssc.201500313Tajima, T., Sakata, W., Wada, T., Tsutsui, A., Nishimoto, S., Miyake, M., & Takaguchi, Y. (2011). Photosensitized Hydrogen Evolution from Water Using a Single-Walled Carbon Nanotube/Fullerodendron/SiO2 Coaxial Nanohybrid. Advanced Materials, 23(48), 5750-5754. doi:10.1002/adma.201103472Ueda, Y., Takeda, H., Yui, T., Koike, K., Goto, Y., Inagaki, S., & Ishitani, O. (2014). A Visible-Light Harvesting System for CO2Reduction Using a RuII-ReIPhotocatalyst Adsorbed in Mesoporous Organosilica. ChemSusChem, 8(3), 439-442. doi:10.1002/cssc.201403194Yokoyama, T., Yokoyama, S., Kamikado, T., Okuno, Y., & Mashiko, S. (2001). Selective assembly on a surface of supramolecular aggregates with controlled size and shape. Nature, 413(6856), 619-621. doi:10.1038/35098059Barth, J. V., Costantini, G., & Kern, K. (2005). Engineering atomic and molecular nanostructures at surfaces. Nature, 437(7059), 671-679. doi:10.1038/nature04166Klasovsky, F., Hohmeyer, J., Brückner, A., Bonifer, M., Arras, J., Steffan, M., … Claus, P. (2008). Catalytic and Mechanistic Investigation of Polyaniline Supported PtO2 Nanoparticles: A Combined in situ/operando EPR, DRIFTS, and EXAFS Study. The Journal of Physical Chemistry C, 112(49), 19555-19559. doi:10.1021/jp805970eNishiyama, F., Yokoyama, T., Kamikado, T., Yokoyama, S., Mashiko, S., Sakaguchi, K., & Kikuchi, K. (2007). Interstitial Accommodation of C60 in a Surface-Supported Supramolecular Network. Advanced Materials, 19(1), 117-120. doi:10.1002/adma.200601364Shalom, M., Inal, S., Fettkenhauer, C., Neher, D., & Antonietti, M. (2013). Improving Carbon Nitride Photocatalysis by Supramolecular Preorganization of Monomers. Journal of the American Chemical Society, 135(19), 7118-7121. doi:10.1021/ja402521sSun, J., Xu, J., Grafmueller, A., Huang, X., Liedel, C., Algara-Siller, G., … Shalom, M. (2017). Self-assembled carbon nitride for photocatalytic hydrogen evolution and degradation of p-nitrophenol. Applied Catalysis B: Environmental, 205, 1-10. doi:10.1016/j.apcatb.2016.12.030Ishida, Y., Chabanne, L., Antonietti, M., & Shalom, M. (2014). Morphology Control and Photocatalysis Enhancement by the One-Pot Synthesis of Carbon Nitride from Preorganized Hydrogen-Bonded Supramolecular Precursors. Langmuir, 30(2), 447-451. doi:10.1021/la404101hZhang, J., Hao, J., Wei, Y., Xiao, F., Yin, P., & Wang, L. (2010). Nanoscale Chiral Rod-like Molecular Triads Assembled from Achiral Polyoxometalates. Journal of the American Chemical Society, 132(1), 14-15. doi:10.1021/ja907535gZheng, Y., Zhou, H., Liu, D., Floudas, G., Wagner, M., Koynov, K., … Ikeda, T. (2013). Supramolecular Thiophene Nanosheets. Angewandte Chemie, 125(18), 4945-4948. doi:10.1002/ange.201210090Lee, E., Kim, J.-K., & Lee, M. (2009). Reversible Scrolling of Two-Dimensional Sheets from the Self-Assembly of Laterally Grafted Amphiphilic Rods. Angewandte Chemie International Edition, 48(20), 3657-3660. doi:10.1002/anie.200900079Kambe, T., Sakamoto, R., Hoshiko, K., Takada, K., Miyachi, M., Ryu, J.-H., … Nishihara, H. (2013). π-Conjugated Nickel Bis(dithiolene) Complex Nanosheet. Journal of the American Chemical Society, 135(7), 2462-2465. doi:10.1021/ja312380bDong, R., Pfeffermann, M., Liang, H., Zheng, Z., Zhu, X., Zhang, J., & Feng, X. (2015). Large-Area, Free-Standing, Two-Dimensional Supramolecular Polymer Single-Layer Sheets for Highly Efficient Electroc