From Mechanically Interlocked Structures to Host–Guest Chemistry Based on Twisted Dimeric Architectures by Adjusting Space Constraints

Abstract

Open AccessCCS ChemistryRESEARCH ARTICLE6 Jun 2022From Mechanically Interlocked Structures to Host–Guest Chemistry Based on Twisted Dimeric Architectures by Adjusting Space Constraints Xin Jiang, Hao Yu, Junjuan Shi, Qixia Bai, Yaping Xu, Zhe Zhang, Xin-Qi Hao, Bao Li, Pingshan Wang, Lixin Wu and Ming Wang Xin Jiang State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 , Hao Yu State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 , Junjuan Shi State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 , Qixia Bai Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou, Guangdong 510006 , Yaping Xu State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 , Zhe Zhang Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou, Guangdong 510006 , Xin-Qi Hao College of Chemistry and Green Catalysis Center, Zhengzhou University, Zhengzhou, Henan 450002 , Bao Li State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 , Pingshan Wang Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou Key Laboratory for Clean Energy and Materials, Guangzhou University, Guangzhou, Guangdong 510006 , Lixin Wu State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 and Ming Wang *Corresponding author: E-mail Address: [email protected] State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin 130012 https://doi.org/10.31635/ccschem.021.202100948 SectionsSupplemental MaterialAboutAbstractPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Mechanically interlocked molecules (MIMs) and host–guest chemistry have received great attention in the past few decades. However, it remains challenging to design architectures with mechanically interlocked features and construct cavities for guest molecule recognition using similar building blocks. In this study, we designed and constructed a series of novel twisted supramolecular structures by assembling various multitopic terpyridine (tpy) ligands with the same diameter and Zn(II) ions. The obtained complexes exhibited evolutional architectures and showed distinctively different space-constraint effects. Specifically, the assembled dimer SA, SB, and SBH displayed mechanically interlocked phenomena, including [2]catenane and [3]catenane, with an increase in concentration. However, no interlocked structures were observed in complexes SC and SCH constructed by hexatopic tpy ligands due to the significant space constraints. The single-crystal data of complex SCH further proved significant space constraints and illustrated the formation of a relatively closed cavity, which showed excellent host–guest properties for different calixarenes, especially high affinity for calix[6]arene. Download figure Download PowerPoint Introduction Inspired by the self-assembly phenomena and functional expressions of natural molecules, such as DNA formation, protein folding or recognition, and enzyme catalysis,1–6 noncovalent molecular interactions, including metal–ligand coordination, hydrogen bonding, π–π interactions, and so on,7–9 have been extensively applied to construct numerous discrete architectures.10–12 Based on the discrete structures, more complex systems formed by intermolecular interactions, such as hierarchical self-assembly,13–15 the mechanically interlocked molecules (MIMs),16–19 and host–guest systems,20–24 have received considerable attention over the past few decades. As widespread structures playing a unique role in living organisms, complex systems inspire the fabrication of aesthetic molecular structures and provide impetus to the development of molecular machines and smart materials.25–30 Coordination-driven self-assembly has served as one of the most effective approaches to construct complex and exquisite discrete architectures, due to the feature of dynamic reversibility and coordination geometry.31–37 In recent years, by employing discrete metallosupramolecular structures, a variety of interlocked architectures have been extensively reported, including rotaxanes,38–40 catenanes,41–44 and knots.45–48 In contrast, many discrete metallosupramolecules have been widely employed in the fabrication of functional host–guest systems, such as catalysis,49,50 molecular binding,51 and drug delivery.52,53 For interlocked and host–guest molecular systems, an appropriate cavity with predesigned interactions and space constraints is the most critical factor for fabricating the interlocked structures and guest encapsulation. Although many types of cavities have been created for complex molecular systems, developing a suitable system to transform interlocked to host–guest structures by simply adjusting space constraints remains a great challenge. 2,2′:6′,2″-Terpyridine derivatives have been widely used to construct numerous novel supramolecular structures54–59 with special applications in diverse fields, including catalysts,60,61 medicines,62 sensors,63,64 smart materials,65,66 and optoelectronic devices.67–69 However, the octahedral coordination geometry of the tpy-M(II)-tpy complex can cause significant steric hindrance, which limits the application in the formation of coordination-directed, instead of templating-directed, mechanically interlocked structures .70–73 On the contrary, the high steric hindrance of tpy-M(II)-tpy is more advantageous to construct a tighter closed cavity for the encapsulation of guest molecules. Herein, we designed and synthesized five ortho-tpy ligands with the same diameter (Scheme 1), denoted as ditopic LA, tritopic LB and LBH, and hexatopic LC and LCH. To reduce the steric congestion of the pseudo-octahedral tpy-M(II)-tpy connection, tpy units were located in the center of the final structures. The corresponding complexes with twisted dimeric structures were successfully constructed through assembling these ligands with Zn(II) ions. The obtained complexes exhibited different space constraints and showed significantly different interlocking or host–guest properties. For metal complexes SA, SB, and SBH, assembled by ditopic ligand LA, and tritopic ligands LB and LBH (without alkyl chains), the obvious self-interlocked phenomena were observed upon increasing the concentration of these complexes, due to their lower space constraints and suitable cavity. However, with further increasing space constraints, the complexes SC and SCH, based on the hexatopic ligands, could only form monomeric twisted prisms, and no interlocking phenomena were observed. Because of the significant space restriction effect, SCH served as a well-sealed cavity for the host–guest properties and efficiently encapsulated the calixarene-type species, especially showing a high affinity for calix[6]arene, with a more complex conformation. Scheme 1 | The self-assembly of twisted dimeric architectures, mechanically interlocked structures, and guest recognition. Conditions: (1) CHCl3/MeOH (1∶3. v/v), 50 °C, 8 h. Download figure Download PowerPoint Experimental Methods All reagents were purchased from Sigma-Aldrich (Chaoyang District, Beijing, China), Acros (Shanghai, China), and Aladdin (Shanghai, China) and used without further purification. Compounds 1,74 2,75 4,76 5,73 7,77 and 878 were synthesized per the literature as reported in Supporting Information Scheme S1. NMR data were recorded at 25 °C on Bruker 500 MHz and 600 MHz (Bruker switzerland AG, Fällanden, Zurich, Switzerland) nuclear magnetic resonance instruments using CDCl3 and CD3CN with tetramethylsilane (TMS) as the solvents. Electrospray ionization mass spectrometry (ESI-MS) and traveling-wave ion mobility mass spectrometry (TWIM-MS) were recorded with a Waters Synapt G2 tandem mass spectrometer (Waters Corporation, Milford, MA, USA). Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was performed on a Bruker Autoflex III (Bruker Corporation, Billerica, MA, USA) using trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-2-propenyli-dene]malononitrile (DCTB) as a matrix. Crystal data were collected from the BL17B beamline of National Facility for Protein Science in Shanghai (NFPS) at Shanghai Synchrotron Radiation Facility. Synthesis of ligand LA Compound 6 (0.9 g, 1.14 mmol), 4,4″-dibromo-p-terphenyl (186.4 mg, 0.48 mmol), Pd(PPh3)2Cl2 (40 mg, 0.058 mmol), and sodium carbonate (1.59 g, 15.0 mmol) were added into a 100 ml Schlenk flask. Toluene (30 mL), H2O (15 mL), and tert-butyl alcohol (6 mL) were added under N2. The mixture was stirred at 85 °C for 24 h. After cooling to room temperature, the solvent was removed under vacuum, and the residue was extracted with CHCl3. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and then concentrated in vacuo. The crude product was purified by column chromatography on silica gel with dichloromethane: ethanol (100∶2) as eluent to afford the product as a white solid (0.49 g, 65%). 1H NMR (500 MHz, CDCl3, 298 K, δ): 8.73 (s, 4H, tpy-H3′,5′), 8.72–8.69 (m, 4H, tpy-H6,6″), 8.66 (d, J = 7.9 Hz, 4H, tpy-H3,3″), 7.87 (td, J = 7.7, 1.8 Hz, 4H, tpy-H4,4″), 7.80 (d, J = 8.2 Hz, 4H, Ph-Hj), 7.70 (d, J = 4.6 Hz, 12H, Ph-Hm, Ph-Ho, and Ph-Hn), 7.55 (d, J = 8.0 Hz, 4H, Ph-Hl), 7.36–7.31 (m, 8H, tpy-H5,5″ and Ph-Hi), 7.27 (m, 4H, Ph-Hk), 7.03 (d, J = 2.2 Hz, 4H, Ph-Ha and Ph-Hb), 4.11 (td, J = 6.6, 3.9 Hz, 8H, Alkyl-Hc′ and Alkyl-Hc′), 1.93–1.88 (m, 8H, Alkyl-Hd and Alkyl-Hd′), 1.52 (8H, Alkyl-He and Alkyl-He′), 1.38 (m, 16H, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′, and Alkyl-Hg′), 0.96–0.89 (m, 12H, Alkyl-Hh and Alkyl-Hh′). 13C NMR (125 MHz, CDCl3, 298 K, δ): 156.40, 156.00, 150.04, 149.24, 148.78, 148.65, 142.60, 140.64, 139.77, 139.51, 138.53, 137.01, 136.25, 132.86, 132.51, 130.66, 130.54, 127.55, 127.50, 127.42, 127.06, 126.72, 123.95, 121.48, 118.83, 116.20, 31.77, 29.45, 25.90, 22.81, 14.23, 0.16. MALDI-TOF-MS (m/z): calcd for [C108H104N6O4]+, 1548.8; found, 1548.8. Synthesis of ligand LB Compound 6 (1.0 g, 1.27 mmol), 1,3,5-tris(4-bromophenyl)benzene (178 mg, 0.33 mmol), Pd(PPh3)2Cl2 (44 mg, 0.064 mmol), and sodium carbonate (1.06 g, 10.0 mmol) were added into a 100 ml Schlenk flask. Toluene (25 mL), H2O (10 ml), and tert-butyl alcohol (3 mL) were added under N2. The mixture was stirred at 85 °C for 3 days. After cooling to room temperature, the solvent was removed under vacuum, and the residue was extracted with CHCl3. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and then concentrated in vacuo. The crude product was purified by column chromatography on silica gel with dichloromethane: ethanol (100∶2.5) as eluent to afford the product as a white solid (0.51 g, 68%). 1H NMR (500 MHz, CDCl3, 298 K, δ): 8.73 (s, 6H, tpy-H3′,5′), 8.71–8.68 (m, 6H, tpy-H6,6″), 8.65 (dd, J = 7.9, 1.1 Hz, 6H, tpy-H3,3″), 7.86–7.83 (m, 9H, tpy-H4,4″, Ph-Ho), 7.82–7.78 (m, 6H, Ph-Hj), 7.77–7.71 (m, 12H, Ph-Hn and Ph-Hm), 7.58–7.52 (m, 6H, Ph-Hl), 7.35–7.30 (m, 12H, Ph-Hi and tpy-H5,5″), 7.27 (m, 6H, Ph-Hk), 7.03 (d, J = 1.4 Hz, 6H, Ph-Ha and Ph-Hb), 4.12 (td, J = 6.6, 4.4 Hz, 12H, Alkyl-Hc and Alkyl-Hc′), 1.88 (m, 12H, Alkyl-Hd and Alkyl-Hd′), 1.52 (m, 12H, Alkyl-He and Alkyl-He′), 1.38 (m, 24H, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′, and Alkyl-Hg′), 0.95–0.89 (m, 18H, Alkyl-Hh and Alkyl-Hh′). 13C NMR (125 MHz, CDCl3, 298 K, δ): 156.35, 155.98, 150.01, 149.22, 148.76, 148.63, 142.58, 142.08, 140.67, 139.99, 138.50, 137.00, 136.23, 132.83, 132.48, 130.65, 130.54, 127.78, 127.58, 127.05, 126.75, 125.03, 123.95, 121.46, 118.81, 116.18, 31.76, 29.44, 25.89, 22.80, 14.22. MALDI-TOF-MS (m/z): calcd for [C159H153N9O6+H]+, 2285.2; found, 2285.2. Synthesis of ligand LBH Compound 3 (1.2 g, 2.0 mmol), 1,3,5-tris(4-bromophenyl)benzene (0.31 g, 0.57 mmol), Pd(PPh3)2Cl2 (70 mg, 0.1 mmol), and sodium carbonate (1.59 g, 15 mmol) were added into a 100 mL Schlenk flask. Toluene (30 mL), H2O (15 mL), and tert-butyl alcohol (5 mL) were added under N2. The mixture was stirred at 85 °C for 3 days. After cooling to room temperature, the solvent was removed under vacuum, and the residue was extracted with CHCl3. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and then concentrated in vacuo. The crude product was purified by column chromatography on silica gel with dichloromethane: ethanol (100∶2.5) as eluent to afford the product as a white solid (0.62 g, 65%). 1H NMR (500 MHz, CDCl3, 298 K, δ): 8.73 (s, 6H, tpy-H3′,5′), 8.69 (dd, J = 4.9, 1.7 Hz, 6H, tpy-H6,6″), 8.65 (d, J = 7.9 Hz, 6H tpy-H3,3″), 7.87–7.79 (m, 15H, tpy-H4,4″, Ph-Hk and Ph-Ha), 7.75 (m, 12H, Ph-Hj and Ph-Hi), 7.57 (d, J = 8.0 Hz, 6H, Ph-Hh), 7.54–7.52 (m, 6H, Ph-Hd and Ph-Hc), 7.51–7.46 (m, 6H, Ph-Hf and Ph-He), 7.35 (d, J = 8.2 Hz, 6H, Ph-Hb), 7.30 (m, 12H, tpy-H5,5″ and Ph-Hg). 13C NMR (125 MHz, CDCl3, δ): 156.38, 156.02, 149.99, 149.23, 142.55, 142.09, 140.61, 140.31, 140.05, 138.85, 136.98, 136.61, 130.86, 130.59, 130.49, 127.97, 127.79, 127.60, 127.10, 126.78, 125.04, 123.94, 121.47, 118.87, 77.42, 77.16, 76.91. MALDI-TOF-MS (m/z): calcd for [C123H81N9]+, 1683.7; found, 1683.7. Synthesis of ligand LC Compound 6 (1.0 g, 1.27 mmol), hexa(4-bromophenyl)-benzene (163 mg, 0.16 mmol), Pd(PPh3)4 (72 mg, 0.064 mmol), and sodium carbonate (1.59 g, 15 mmol) were added into a 100 mL Schlenk flask. Toluene (30 mL), H2O (15 mL), and tert-butyl alcohol (5 mL) were added under N2. The mixture was stirred at 85 °C for 6 days. After cooling to room temperature, the solvent was removed under vacuum, and the residue was extracted with CHCl3. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and then concentrated in vacuo. The crude product was purified by column chromatography on silica gel with dichloromethane: ethanol (100∶3.5) as eluent to afford the product as a white solid (251 mg, 35%). 1H NMR (500 MHz, CDCl3, 298 K, δ): 8.60 (s, 12H, tpy-H3′,5′), 8.56 (d, J = 4.8 Hz, 12H, tpy-H6,6″), 8.52 (d, J = 8.0 Hz, 12H, tpy-H3,3″), 7.74 (td, J = 7.8, 1.8 Hz, 12H, tpy-H4,4″), 7.63 (d, J = 7.9 Hz, 12H, Ph-Hj), 7.28 (m, 12H, Ph-Hn), 7.16 (m, 36H, tpy-H5,5″, Ph-Hi and Ph-Hl), 7.00 (d, J = 8.2 Hz, 12H, Ph-Hm), 6.93 (s, 6H, Ph-Ha), 6.89–6.83 (m, 18H, Ph-Hk and Ph-Hb), 4.08–3.96 (m, 24H, Alkyl-Hc and Alkyl-Hc′), 1.87–1.77 (m, 24H, Alkyl-Hd and Alkyl-Hd′), 1.51–1.42 (m, 24H, Alkyl-He and Alkyl-He′), 1.39–1.29 (m, 48H, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′, and Alkyl-Hg′), 0.92–0.83 (m, 36H, Alkyl-Hh and Alkyl-Hh′). 13C NMR (125 MHz, CDCl3, δ): 156.16, 155.70, 149.55, 148.95, 148.61, 148.35, 142.32, 139.88, 138.53, 136.68, 135.78, 132.81, 131.83, 130.35, 130.00, 129.45, 126.74, 126.34, 125.23, 125.22, 123.64, 121.21, 118.50, 116.25, 116.24, 115.63, 31.59, 29.28, 25.73, 22.61, 14.03. MALDI-TOF-MS (m/z): calcd for [C312H300N18O12+H]+, 4491.3; found, 4491.3. Synthesis of ligand LCH Compound 3 (1.5 g, 2.6 mmol), hexa(4-bromophenyl)-benzene (328 mg, 0.33 mmol), Pd(PPh3)4 (150 mg, 0.13 mmol), and sodium carbonate (1.59 g, 15 mmol) were added into a 100 mL Schlenk flask. Toluene (30 mL), H2O (15 mL), and tert-butyl alcohol (4 mL) were added under N2. The mixture was stirred at 85 °C for 6 days. After cooling to room temperature, the solvent was removed under vacuum, and the residue was extracted with CHCl3. The combined organic layer was washed with brine, dried over anhydrous Na2SO4, and then concentrated in vacuo. The crude product was purified by column chromatography on silica gel with dichloromethane: ethanol (100∶3.5) as eluent to afford the product as a white solid (0.47 g, 43%). 1H NMR (500 MHz, CDCl3, 298 K, δ): 8.59 (s, 12H, tpy-H3′,5′), 8.58–8.55 (m, 12H, tpy-H6,6″), 8.51 (d, J = 8.0 Hz, 12H, tpy-H3,3″), 7.74 (td, J = 7.7, 1.8 Hz, 12H, tpy-H4,4″), 7.64 (d, J = 8.1 Hz, 12H, Ph-Ha), 7.43–7.34 (m, 18H, Ph-Hc, Ph-Hd, and Ph-He), 7.30 (d, J = 7.4 Hz, 6H, Ph-Hf), 7.29 (s, 12H, Ph-Hj), 7.19 (ddd, J = 7.5, 4.7, 1.2 Hz, 12H, tpy-H5,5″), 7.15 (d, J = 8.0 Hz, 12H, Ph-Hb), 7.11 (d, J = 8.0 Hz, 12H, Ph-Hh), 6.99 (d, J = 8.1 Hz, 12H, Ph-Hi), 6.86 (d, J = 8.0 Hz, 12H, Ph-Hg). 13C NMR (125 MHz, CDCl3, δ): 156.26, 155.82, 149.66, 149.09, 142.44, 140.36, 140.25, 139.90, 139.83, 138.97, 137.07, 136.84, 136.24, 131.96, 130.94, 130.78, 130.41, 130.08, 127.82, 127.10, 126.92, 126.50, 125.41, 123.80, 121.38, 118.68. MALDI-TOF-MS (m/z): calcd. for [C240H156N18]+, 3289.3; found, 3289.3 Synthesis of complex SA To a solution of ligand LA (10.0 mg, 6.5 μmol) in CHCl3 (3 mL), a solution of Zn(NO3)2·6H2O (1.9 mg, 6.4 μmol) in MeOH (9 mL) was added. The mixture was stirred at 50 °C for 8 h and then cooled to room temperature. Upon addition of NH4PF6 (100 mg), a precipitate was formed and washed with water to give a white product (10.6 mg). 1H NMR (500 MHz, CD3CN, 298 K, δ): 8.95 (s, 8H, tpy-H3′,5′), 8.68 (d, J = 8.1 Hz, 8H, tpy-H3,3″), 8.10–8.14 (m, 16H, tpy-H4,4″, Ph-Hj), 7.79 (m, 32H, tpy-H6,6″, Ph-Hm, Ph-Hn, and Ph-Ho), 7.65 (d, J = 8.0 Hz, 8H, Ph-Hl), 7.57 (d, J = 8.1 Hz, 8H, Ph-Hi), 7.36 (m, 16H, Ph-Hk and tpy-H5,5″), 7.13 (s, 4H, Ph-Ha), 7.10 (s, 4H, Ph-Hb), 4.14 (q, J = 6.9 Hz, 16H, Alkyl-Hc and Alkyl-Hc′), 1.84 (m, 16H, Alkyl-Hd and Alkyl-Hd′), 1.53 (m, 16H, Alkyl-He and Alkyl-He′), 1.42–1.36 (m, 32H, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′, and Alkyl-Hg′), 0.98–0.90 (m, 24H, Alkyl-Hh and Alkyl-Hh′). 13C NMR (125 MHz, CD3CN, 298 K, δ) 155.50, 149.77, 149.05, 148.62, 147.94, 147.84, 144.94, 141.63, 141.14, 140.79, 139.64, 139.57, 138.16, 133.55, 132.72, 131.60, 131.25, 130.69, 127.84, 127.48, 127.43, 127.22, 126.43, 124.66, 123.16, 120.99, 116.11, 31.34, 29.13, 25.53, 22.40, 13.36. ESI-MS (m/z): 1760.3 [M-2PF6−]2+ (calcd: 1760.3), 1125.0 [M-3PF6−]3+ (calcd: 1125.0), 807.5 [M-4PF6−]4+ (calcd: 807.5). Synthesis of complex SB To a solution of ligand LB (8.0 mg, 3.5 μmol) in CHCl3 (3 mL), a solution of Zn(NO3)2·6H2O (1.6 mg, 5.4 μmol) in MeOH (9 mL) was added. The mixture was stirred at 50 °C for 8 h and then cooled to room temperature. Upon addition of NH4PF6 (100 mg), a precipitate was formed and washed with water to give a white product (9.1 mg). 1H NMR (500 MHz, CD3CN, 298 K, δ): 8.94 (s, 12H, tpy-H3′,5′), 8.67 (d, J = 8.1 Hz, 12H, tpy-H3,3″), 8.11 (d, J = 7.8 Hz, 24H, tpy-H4,4″ and Ph-Hj), 7.98–7.86 (m, 18H, Ph-Ho and Ph-Hn), 7.78 (m, 24H, Ph-Hm and Ph-Hl), 7.63 (d, J = 7.7 Hz, 12H, tpy-H6,6″), 7.56 (d, J = 8.0 Hz, 12H, Ph-Hi), 7.34 (m, 24H, Ph-Hk and tpy-H5,5″), 7.14 (s, 6H, Ph-Ha), 7.09 (s, 6H, Ph-Hb), 4.19–4.06 (m, 24H, Alkyl-Hc and Alkyl-Hc′), 1.84 (s, 24H, Alkyl-Hd and Alkyl-Hd′), 1.53 (s, 24H, Alkyl-He and Alkyl-He′), 1.42–1.36 (m, 48H, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′ and Alkyl-Hg′), 0.96–0.90 (m, 36H, Alkyl-Hh and Alkyl-Hh′). ESI-MS (m/z): 1734.1 [M-3PF6−]3+ (calcd: 1734.1), 1264.5 [M-4PF6−]4+ (calcd: 1264.5), 982.4 [M-5PF6−]5+ (calcd: 982.4), 794.5 [M-6PF6−]6+ (calcd: 794.5). Synthesis of complex SBH To a solution of ligand LBH (10.0 mg, 5.9 μmol) in CHCl3 (3 mL), a solution of Zn(NO3)2·6H2O (2.6 mg, 8.9 μmol) in MeOH (9 mL) was added. The mixture was stirred at 50 °C for 8 h and then cooled to room temperature. Upon addition of NH4PF6 (100 mg), a precipitate was formed and washed with water to give a white product (11.8 mg). 1H NMR (500 MHz, CD3CN, 298 K, δ): 8.95 (s, 12H, tpy-H3′,5′), 8.67 (d, J = 8.1 Hz, 12H, tpy-H3,3″), 8.15–8.06 (m, 24H, Ph-Ha and tpy-H4,4″), 7.96 (s, 6H, Ph-Hk), 7.90 (d, J = 8.0 Hz, 12H, Ph-Hj), 7.78 (m, 24H, tpy-H6,6″ and Ph-Hi), 7.66 (d, J = 8.0 Hz, 12H, Ph-Hh), 7.63–7.56 (m, 36H, Ph-Hd, Ph-Hc, Ph-He, Ph-Hb, and Ph-Hf), 7.38 (d, J = 8.0 Hz, 12H, Ph-Hg), 7.34 (dd, J = 7.7, 5.2 Hz, 12H, tpy-H5,5″). 13C NMR (125 MHz, CD3CN, 298 K, δ) 149.79, 147.96, 144.92, 141.62, 141.16, 140.77, 140.04, 139.24, 138.49, 136.69, 135.19, 134.83, 134.01, 133.67, 131.14, 130.70, 130.58, 128.53, 128.07, 127.84, 127.58, 127.44, 127.26, 126.49, 124.67, 123.17, 121.11. ESI-MS (m/z): 1333.6 [M-3PF6−]3+ (calcd: 1333.6), 963.7 [M-4PF6−]4+ (calcd: 963.7), 742.0 [M-5PF6−]5+ (calcd: 742.0), 594.1 [M-6PF6−]6+ (calcd: 594.1). Synthesis of complex SC To a solution of ligand LC (6.0 mg, 1.34 μmol) in CHCl3 (2 mL), a solution of Zn(NO3)2·6H2O (1.2 mg, μmol) in MeOH (6 mL) was added. The mixture was stirred at 50 °C for 8 h and then cooled to room temperature. Upon addition of NH4PF6 mg), a precipitate was formed and washed with water to give a white product mg, 1H NMR (500 MHz, CD3CN, 298 K, δ): (s, 24H, tpy-H3′,5′), 8.59 (d, J = 8.0 Hz, 24H, tpy-H3,3″), J = Hz, 24H, tpy-H4,4″), 7.70 (d, J = Hz, 24H, tpy-H6,6″), (d, J = 7.8 Hz, 24H, Ph-Hj), (m, 48H, Ph-Hn and Ph-Hl), (m, and tpy-H5,5″), 7.15 (d, J = 7.9 Hz, 24H, Ph-Hm), (m, 24H, Ph-Ha and Ph-Hb), (s, 48H, Alkyl-Hc and Alkyl-Hc′), (d, J = Hz, 48H, Alkyl-Hd and Alkyl-Hd′), (s, 48H, Alkyl-He and Alkyl-He′), (s, Alkyl-Hf, Alkyl-Hg, Alkyl-Hf′, and Alkyl-Hg′), (s, Alkyl-Hh and Alkyl-Hh′). 13C NMR (125 MHz, CD3CN, 298 K, δ) 132.48, 127.22, 25.53, ESI-MS (m/z): [M-5PF6−]5+ (calcd: [M-6PF6−]6+ (calcd: (calcd: (calcd: (calcd: (calcd: Synthesis of complex SCH To a solution of ligand LCH (6.0 mg, μmol) in CHCl3 (2 mL), a solution of Zn(NO3)2·6H2O (1.6 mg, 5.4 μmol) in MeOH (6 mL) was added. The mixture was stirred at 50 °C for 8 h and then cooled to room temperature. Upon addition of NH4PF6 mg), a precipitate was formed and washed with water to give a white product mg, 1H NMR (500 MHz, CD3CN, 298 K, δ): (s, 24H, tpy-H3′,5′), 8.60 (d, J = 8.1 Hz, 24H, tpy-H3,3″), (td, J = 7.7, Hz, 24H, tpy-H4,4″), 7.70 (d, J = 4.8 Hz, 24H, tpy-H6,6″), (d, J = 7.9 Hz, 24H, Ph-Ha), (m, and Ph-Hh), (dd, J = Hz, 12H, Ph-Hc), (dd, J = Hz, 12H, Ph-He), (m, 36H, Ph-Hd and Ph-Hb), (dd, J = 5.2 Hz, 24H, tpy-H5,5″), 7.16 (m, 36H, and 13C NMR (125 MHz, CD3CN, 298 K, δ) 147.94, 140.25, 131.83, 128.53, 125.03, ESI-MS (m/z): [M-5PF6−]5+ (calcd: [M-6PF6−]6+ (calcd: (calcd: (calcd: (calcd: and and interlocking of complex SA The to ligand (without alkyl was of the of To the alkyl were into ligand The 1H NMR of ligand LA and corresponding complex SA exhibited one of and Supporting Information and the formation of a with ligand LA, the of SA were due to the lower the at the of tpy were significantly based on the The of 1H NMR were by All NMR and and data of ligand LA and complex SA were in Supporting Information 1 | 1H NMR (500 MHz, 298 of LA in CDCl3, and in Download figure Download PowerPoint the 1H NMR significantly upon increasing the concentration of Specifically, on tpy with increasing concentration from to and Supporting Information and and a of this and the of the on the LA and exhibited a significant with the the on the displayed an and a similar with and phenomena as the concentration obvious interactions SA the the NMR was employed to the of the as further we observed a = at a lower concentration and = at a concentration. The the were 1.4 at and 1.8 at Supporting Information and and an interlocked formed by or more SA (Scheme at high concentration. In the steric hindrance of it is to the on the were through π–π to form interlocked structures, instead of the ESI-MS was used to the molecular of In only one of with different from to was observed at a concentration of due to the of a different of The of with the of SA and Supporting Information for the dimer with a molecular of Upon SA a at for was observed which was the molecular of SA, the formation of [2]catenane a the of the at of for further the formation of and Supporting Information | ESI-MS of complex SA at a concentration of and for [2]catenane and at high concentration as Download figure Download PowerPoint and interlocking of complexes SB and SBH To further the of space constraints on the and of the complex SB, based on tritopic ligand was obtained through the same as in Supporting Information Scheme The 1H NMR of SB showed one of with similar to SA Supporting Information The at upon of the effect, were The of were through the All NMR and and data of ligand LB and corresponding complex SB were in Supporting Information The ESI-MS of complex SB displayed a series of from to Supporting Information The and with the of SB with a molecular of To the of or was as an of As in Supporting Information showed a no or of the in this further the concentration of SB by using 1H NMR

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