Coordination-Driven Self-Assembly of Heterotrimetallic Barrel and

Oct 16, 2017 - Co(I)−Fe(II)−Pd(II) heterotrimetallic trifacial barrel 1, which ... The structures of molecular barrel 1 and prismatic cage 3 were ...
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Coordination-Driven Self-Assembly of Heterotrimetallic Barrel and Bimetallic Cages Using a Cobalt Sandwich-Based Tetratopic Donor Nem Singh,†,‡ Jatinder Singh,†,‡ Dongwook Kim,§ Dong Hwan Kim,† Eun-Hee Kim,⊥ Myoung Soo Lah,§ and Ki-Whan Chi*,† †

Department of Chemistry, University of Ulsan, Ulsan 44610, Republic of Korea Department of Chemistry, Ulsan National Institute of Science & Technology, Ulsan 44919, Republic of Korea ⊥ Republic of Korea Protein Structure Group, Korea Basic Science Institute, Ochang, Chungbuk 28119, Republic of Korea §

S Supporting Information *

ABSTRACT: Three-dimensional molecular architectures selfassembled with tripodal and tetratopic donors are valuable because of their encapsulation properties. Here, we present Co(I)−Fe(II)−Pd(II) heterotrimetallic trifacial barrel 1, which was self-assembled using a newly synthesized tetratopic donor [CpCo(CbR4)] [L; Cp = cyclopentadienyl, Cb = cyclobudiene, and R = 4-(4-pyridylphenyl)] and a 90° acceptor [cis-(dppf)Pd(OTf)2] (A1; dppf = (diphenylphosphino)ferrocene and OTf = CF3SO3−). The heterotrimetallic barrel 1 exhibited selective 1:1 interaction with a N,N′-dimethyl-1,4,5,8-naphthalenetetracarboxylic diimide guest, as revealed by 1H NMR analysis. The self-assembly of donor L with two other Ru(II)-based 180° acceptors [(p-cymene)2Ru2(OO∩OO)(OTf)2] [OO∩OO = 6,11-dioxido-5,12-naphthacenedione (A2) and oxalate (A3)] resulted in tetragonal-prismatic cages. Self-assembly using the longer acceptor A2 provided rare isomers of a tetragonal-prismatic cage by varying the orientation of the cyclopentadienyl moiety out−out (2a) or out−in (2b) of the cavity, whereas self-assembly using the shorter acceptor A3 selectively resulted in the tetragonal-prismatic cage 3. The three-dimensional molecular architectures 1−3 were characterized by combined spectroscopic and elemental analyses. The structures of molecular barrel 1 and prismatic cage 3 were elucidated by single-crystal X-ray analysis.

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INTRODUCTION Coordination-driven self-assembly1−5 provides a well-established means of constructing new two-dimensional (2D) and threedimensional (3D) architectures of different sizes,6−8 geometries,9 and topologies.10−14 The resulting self-assembled architectures not only are aesthetically attractive but also have biological,15,16 photophysical,17−19 and catalytic applications.20−23 2D architectures obtained by the self-assembly of ditopic donors are used in sensing,24−28 DNA binding,29,30 the study of molecular topology31−33 and have also shown antitumor properties.34−37 3D architectures are self-assembled mainly using tritopic and tetratopic donors and have exciting encapsulation-based uses for drug delivery,38−40 host−guest chemistry,41−43 and cage catalysis.20−23 The hollow cavities of 3D architectures are extremely useful because their dimensions and functionalities can be tailored accordingly using suitable donors and acceptors.44−46 A number of planar tetratopic donors have been employed in combination with 90° and 180° acceptors to produce trigonal,47,48 tetragonal,49−51 pentagonal,52 and hexagonal53 molecular architectures. The resulting geometries of self-assembled 3D architectures are not solely governed by the lengths and angles of the donors and acceptors; they also depend on the thermodynamic stabilities of the products.52,54 Accordingly, the geometries of the © XXXX American Chemical Society

resulting self-assembled architectures are not easy to predict, and thus new donors and acceptors facilitate innovative possibilities. Cobalt sandwich-based symmetric tetratopic donors have been well investigated and are appreciated because of their potential to provide unique face-based conformational isomerism.55−62 Previously, two such symmetrical tetratopic donors with different dimensions have been employed in combination with Pt(II)- and Pd(II)-based acceptors to produce trigonal and tetragonal barrels.55−62 Here we introduce a new medium-sized cobalt sandwichbased donor, which upon self-assembling with a 90° (diphenylphosphino)ferrocene-based Pd(II) acceptor resulted in the formation of a unique heterotrimetallic barrel. The new donor when self-assembled with a larger 180° p-cymene-based Ru(II) acceptor provided interesting isomers of a tetragonal-prismatic cage by varying the orientation of the cyclopentadienyl moiety out−out or out−in of the cavity, whereas a similar shorter 180° acceptor selectively delivered a tetragonal cage. Special Issue: Self-Assembled Cages and Macrocycles Received: October 16, 2017

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DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

Scheme 1. Self-Assembly of the Molecular Barrel 1: Partial 1H NMR of (a) Acceptor A1, (b) Donor L, and (c) Molecular Barrel 1 and (d) 1H DOSY NMR of Molecular Barrel 1

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RESULTS AND DISCUSSION Synthesis and Characterization of the Tetratopic Donor L and Molecular Barrel 1. We designed and synthesized the tetratopic donor L by a Suzuki cross-coupling reaction using the previously described70 precursor [CpCo{C4(4-PhBr)4}] and 4-pyridylboronic acid. Donor L was purified by column chromatography and isolated in 87% yield (Figures S1 and S2). The heterotrimetallic barrel 1 was synthesized as shown in Scheme 1: a mixture of 2 equiv of acceptor A1 and 1 equiv of donor L in CD3OD/CD3NO2 (1:1) for 12 h with stirring resulted in a clear reddish solution. The extremely simple 1H NMR spectrum of 1 and significant upfield shift of α- and β-pyridyl protons indicated the presence of metal−ligand coordination and the formation of a self-assembled molecular architecture (Scheme 1). Only one diffusion coefficient at D = 4.6 × 10−10 m2 s−1 in the DOSY NMR spectrum of 1 confirmed the selective formation of the molecular architecture 1 (Figures S3−S5). The molecular structure of 1 was evidenced by 1H, 13C, and DOSY NMR and elemental analysis and confirmed by single-crystal X-ray diffraction (XRD; Figure 2). Synthesis and Characterization of Tetragonal-Prismatic Cages 2 and 3. During our extensive studies of the

coordination-driven self-assembly of p-cymene Ru(II)-derived 180° acceptors with pyridyl-based donors of various sizes and functionalities, we have identified many topologically interesting molecular architectural features, including a Hopf link,63,64 a molecular Solomon link,65 a noncatenane “rectangle-inrectangle”,66 Borromean rings,67 and an interlocked prismatic cage.68 Therefore, we decided to explore the self-assembly of tetratopic donor L with p-cymene Ru(II)-derived 180° acceptors A2 and A3 using the procedure similar to that for the synthesis of 1. A mixture of donor L and acceptor A2 (1:2 mole ratio) in CD3OD/CD3NO2 (1:1) was stirred for 12 h, after which the reaction mixture turned into a clear greenish color solution (Scheme 2). The 1H NMR spectrum of the resultant showed duplicates of all expected peaks and the presence of only one diffusion coefficient at D = 5.8 × 10−10 m2 s−1 in the DOSY NMR spectrum, indicating the formation of an interlocked cage (Figures S6−S8). However, when the 1H NMR spectrum was analyzed more closely, integration of the duplicate peaks indicated that they were unequal, whereas if the molecules had been interlocked, the integrated areas of the duplicate peaks would have been the same. Resolved electrospray ionization (ESI)-high-resolution mass spectrometry (HRMS) peaks at 1786.1727 ([2 − 3OTf]3+) and 1302.3910 ([2 − 4OTf]4+), which agreed perfectly with the theoretical values B

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry Scheme 2. Coordination-Driven Self-Assembly and Molecular Structures of Tetragonal-Prismatic Cages with the Cyclopentadienyl Ring Positioned Out−Out in 2a, Out−In in 2b, and Out−Out in 3

one Cp outside and another inside 2b. The formation of a third isomer with both Cp entities inside the cavity was not observed possibly because of an inadequate cavity space. All efforts to crystallize a mixture of isomers 2a and 2b failed, and thus we carried out the self-assembly of donor L with the shorter acceptor A3 under identical conditions and obtained a yellow crystalline

and supported the noninterlocked structure (Figures 1 and S13). The 1H ROESY NMR spectrum also did not present any coupling interactions to support the interlocked cage formation (Figure S9). Collective 1H, DOSY, and ROESY NMR with ESI-HRMS evidently supported the formation of isomers 2a and 2b, as shown in Scheme 2, with both Cp entities outside the cavity of 2a and

Figure 1. Calculated (blue, top) and experimental (red, bottom) ESI-MS spectra of the tetragonal-prismatic cages 2 and 3. C

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

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Figure 2. X-ray crystal structure of the molecular barrel 1 presented as a stick model: side view (left) and top view (right). H atoms and counteranions are omitted for clarity.

powder. The clean 1H NMR spectrum of the resultant and ESIHRMS peaks at 1519.4254 ([3 − 3OTf]3+) and 1102.3292 ([3 − 4OTf]+4), which agreed perfectly with the calculated values, confirmed the selective formation of the prismatic cage 3 (Figures 1 and S14). The structure of 3 was confirmed further by singlecrystal XRD analysis (Figure 3). X-ray Structures of the Molecular Barrel 1 and Tetragonal-Prismatic Cage 3. X-ray crystal structures of 1 showed that it consisted of three donors (L) connected together by six Pd(II) acceptors (A1) to form a trigonal barrel, and those of 3 showed that it consisted of four donors and two acceptors in tetragonal-prismatic cage geometry (refer to Figures 2 and 3, respectively). For XRD studies, single crystals of 1 and 3 were grown by the slow vapor diffusion of ether into saturated nitromethane/methanol solutions of 1 and 3. XRD data were collected using synchrotron radiation. Structural refinements revealed that molecular barrel 1 crystallized in the triclinic system with space group P1̅, and the geometry of the six palladium

centers resembled a distorted trigonal-prismatic barrel with two triangular faces and three rectangular sides (Figure S21). Fe(II) and Pd(II) took the vertex of the prismatic barrel, whereas Co(I) occupied a central position of the rectangular faces. The sides of the triangular faces of 1 ranged from 12.147 to 17.334 Å, and the heights of its rectangular faces are 15.319−17.522 Å with an average Pd−N bond distance of 2.095 Å. Structural refinements of 3 showed that it crystallized in the monoclinic system with space group C2/c. Half of the molecular rectangles and five triflate anions in 3 constituted an asymmetric unit. The outer geometry of 3 is that of an irregular tetragonal prism (parallelepiped-shaped), with the sides of the parallelogram faces varying from 15.529 to 17.278 Å and the height averaged at 5.484 Å. Guest Encapsulation Study Using the Molecular Barrel 1. The application prospective of molecular cages in catalysis, host−guest chemistry, and drug delivery is governed by their guest-encapsulation properties. To study the encapsulation and solubilization properties of the molecular barrel 1, six guests, namely,

Figure 3. X-ray crystal structure of the tetragonal-prismatic cage 3 presented as a stick model: side view (left) and top view (right). H atoms and counteranions are omitted for clarity. D

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry

was performed under displacement parameter restraints such as DANG, DELU, DFIX, ISOR, and SIMU. The final refinement was performed with modification of the structure factors for the electron densities of the disordered solvents and triflate anions using the SQUEEZE option of PLATON.76 All non-H atoms were refined anisotropically, whereas the H atoms were assigned isotropic displacement coefficients U(H) = 1.2U(C) and 1.5U(Cmethyl), and their coordinates were allowed to ride on their respective atoms. Full refinement parameters of 1 and 3 are provided in Tables S1 and S2. respectively. Synthesis of Tetratopic Donor L. A mixture of 2 M aqueous K2CO3 (5 mL) and dioxane (15 mL) was taken into a 50 mL roundbottomed flask and degassed with argon for 15 min. To this mixture was added 0.25 mmol (199.0 mg) of the precursor [{η4-C4(4-PhBr)4}Co(η5-C5H5)],25 1.25 mmol (153.6 mg) of 4-pyridylboronic acid, and 25 μmol (28.9 mg) of Pd(PPh3)4, and the mixture was stirred for 24 h at 100 °C under an argon atmosphere. The crude product was concentrated under reduced pressure and purified by column chromatography on silica gel (98:2 dichloromethane/methanol) to afford the product as a yellow solid (192 mg, 83%). 1H NMR (300 MHz, CD3OD/CD3NO2): δ 8.61 (d, J = 6.2 Hz, 8H), 7.77 (d, J = 6.4 Hz, 8H), 7.72 (s, 16H), 4.83 (s, 5H). 13C NMR (75 MHz, CDCl3/CD3OD): δ 149.89, 147.63, 137.90, 134.58, 129.18, 126.64, 121.58, 83.21, 74.26. MS (ESI). Calcd for C53H37CoN4 m/z 788.2350. Found: m/z 788.2334. Mp: 230−232 °C (dec). Anal. Calcd for C53H37CoN4: C, 80.70; H, 4.73; N, 7.10. Found: C, 80.45; H, 4.81; N, 7.17. Synthesis of the Molecular Barrel 1. The acceptor A1 (7.7 mg, 8.0 μmol) and donor L (3.2 mg, 4.0 μmol) were accurately weighed in a reaction vial, 1 mL of MeOH/MeNO2 (1:1) was added, and the mixture was then stirred at room temperature for 12 h. To the resulting clear reddish solution was added dropwise diethyl ether to obtain a reddish precipitate of 1, which was washed twice with diethyl ether, centrifuged, and dried. Yield: 95%. 1H NMR (300 MHz, CD3OD/CD3NO2): δ 8.32 (d, J = 3.0 Hz, 8H), 7.96 (m, 16H), 7.78 (m, 8H), 7.67 (m, 16H), 7.27 (d, J = 4.2 Hz, 8H), 4.81 (s, 8H), 4.82 (s, 8H), 4.71 (s, 5H). 13C NMR (200 MHz, CD3OD/CD3NO2): δ 152.37, 151.27, 140.65, 135.79, 135.67, 134.72, 134.51, 131.40, 130.67, 128.28, 125.18, 84.65, 78.66, 78.54, 77.65, 75.40. Mp: 221−223 °C (dec). Anal. Calcd for C375H279Co3F36Fe6N12O36P12Pd6S12: C, 55.47; H, 3.46; N, 2.07. Found: C, 55.60; H, 3.42; N, 2.06. Synthesis of the Tetragonal-Prismatic Isomers 2a and 2b. Acceptor A2 (8.5 mg 8.0 μmol) and donor L (3.2 mg, 4.0 μmol) were accurately weighed in a reaction vial, 1 mL of MeOH/MeNO2 (1:1) was added, and the mixture was stirred at room temperature for 12 h. To the resulting clear greenish solution was added dropwise diethyl ether to obtain darkgreen precipitate, which was washed twice with diethyl ether, centrifuged, and dried. Yield: 93%. 1H NMR (800 MHz, CD3OD/CD3NO2): δ 8.87−8.74 (m, 5H), 8.58 (d, J = 5.1 Hz, 2H), 8.51 (d, J = 5.5 Hz, 2H), 8.09−7.93 (m, 5H), 7.55 (d, J = 5.1 Hz, 2H), 7.42 (d, J = 5.2 Hz, 2H), 7.35 (d, J = 7.6 Hz, 2H), 7.32 (d, J = 7.8 Hz, 2H), 7.20 (d, J = 7.7 Hz, 2H), 7.14 (d, J = 7.9 Hz, 2H), 5.98 (dd, J = 9.9, 6.0 Hz, 5H), 5.75 (dd, J = 10.9, 5.9 Hz, 5H), 4.29 (s, 1H), 3.83 (s, 1H), 3.03 (dt, J = 13.9, 7.0 Hz, 1H), 3.00−2.95 (m, 1H), 2.25 (s, 3H), 2.21 (s, 3H), 1.38 (d, J = 7.0 Hz, 6H), 1.35 (d, J = 7.1 Hz, 7H). 13C NMR (200 MHz, CD3OD/CD3NO2): δ 169.07, 169.03, 151.79, 150.57, 150.22, 138.86, 138.37, 133.81, 133.74, 133.32, 132.79, 129.52, 128.86, 126.99, 126.51, 126.36, 122.88, 122.63, 121.38, 119.79, 107.03, 106.88, 103.77, 103.65, 99.68, 99.54, 84.09, 84.00, 83.93, 83.29, 82.40, 82.26, 73.85, 73.56, 30.66, 30.61, 21.22, 21.20, 16.59, 16.54. MS (ESI). Calcd for [2-OTf]3+: m/z 1301.20. Found: m/z 1301.21. Calcd for [2-4OTf]4+: m/z 1786.18. Found: m/z 1786.17. Mp: 216−218 °C (dec). Anal. Calcd for C266H218Co2F24N8O40Ru8S8: C, 55.03; H, 3.79; N, 1.93. Found: C, 54.79; H, 3.90; N, 1.89. Synthesis of the Tetragonal-Prismatic Cage 3. Acceptor A3 (6.9 mg, 8.0 μmol) and donor L (3.2 mg, 4.0 μmol) were accurately weighed in a reaction vial, 1 mL of MeOH/MeNO2 (1:1) was added, and the mixture was stirred at room temperature for 12 h. To the resulting clear yellow solution was added dropwise diethyl ether to obtain a yellow precipitate of 3, which was washed twice with diethyl ether, centrifuged, and dried. Yield: 96%. 1H NMR (300 MHz, CD3OD/CD3NO2): δ 8.06 (d, J = 6.6 Hz, 8H), 7.70 (d, J = 6.7 Hz, 8H), 7.54 (m, 8H), 7.45 (m, 8H), 5.93 (d, J = 6.3 Hz, 8H), 5.74 (d, J = 6.3 Hz, 8H), 2.88 (m, 2H), 2.21 (s, 12H), 1.38

pyrene (G1), perylene (G2), coronene (G3), N,N′-dimethyl-1,4,5, 8-naphthalenetetracarboxylic diimide (NDI or G 4 ), N, N′-dimethyl-3,4,9,10-perylenetetracarboxylic diimide (G5), and fullerene C60 (G6) (Figure S15), with electron densities different from each other, were used. These guests are also chosen because of the similarity to the approximate size of the cavity of the molecular barrel 1. From 0.1 to 4 equiv of guests G1−G6 was stirred with the molecular barrel 1 in CD3NO2/CD3OD or CD3CN, and 1 H NMR spectra were recorded after 4 h (Figures S15−S20). 1 H NMR analysis indicated that only the NDI guest showed selective 1:1 interaction with the molecular barrel 1. Although the guest G4 is only sparingly soluble in CD3NO2/CD3OD or CD3CN, the solubility significantly increased in the ratio of 1:1 upon interaction with the molecular barrel 1 (Figures S18 and S19). Broadening of the guest peaks with increasing concentration indicated reversible binding instead of irreversible encapsulation. No other chosen guest showed encapsulation or interaction with the molecular barrel 1.

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CONCLUSIONS A Pd(II)−Co(I)−Fe(II) heterotrimetallic barrel was selectively produced by self-assembly and characterized by spectroscopic and elemental analysis. Single-crystal XRD established the structure as a prismatic molecular barrel with cyclopentadienyl moieties directing away from the cavity. Coordination-driven self-assembly using the tetracene-based ruthenium(II) acceptor provided a mixture of rare position isomers, as evidenced by high-resolution 2D NMR and ESI-MS. 1H NMR analysis showed selective 1:1 interaction of the heterotrimetallic barrel with the NDI guest. The shorter oxalate-based Ru(II) acceptor selectively produced a Co(I)−Ru(II) heterobimetallic tetragonal prism, which supports the notion that the acceptor length governs the positions of the cyclopentadienyl rings in the resulting cages. Efforts are being made in our laboratory to separate or selectively self-assemble the position isomers by guest temptation and use them in selective encapsulation.

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EXPERIMENTAL DETAILS

General Methods. The (diphenylphosphino)ferrocene-based acceptor A153 and the p-cymeneruthenium(II)-derived acceptors A269 and A3, 70 the precursor [{η 4 -C 4 (4-PhBr) 4 }Co(η 5 -C 5 H 5 )], 71 N,N′-dimethyl-1,4,5,8-naphthalenetetracarboxylic diimide (G4),72 and N,N′-dimethyl-3,4,9,10-perylenetetracarboxylic diimide (G5)72 were prepared as previously described. All other reagents were acquired commercially (Sigma-Aldrich, TCI Korea, and Alfa Aesar) and used as received. The solvents used were dried and distilled using standard procedures. 1H, 13C, 1H−1H ROESY, and DOSY NMR spectra were recorded on Bruker 300 MHz (University of Ulsan) and 600 or 800 MHz (Korea Basic Science Institute) spectrometers. NMR chemical shifts in the NMR spectra are reported in parts per million relative to the residual protons of deuterated CD3OD (3.31 ppm) and deuterated CD3NO2 (4.33 ppm). ESI-MS data of 1−3 were obtained using a Synapt G2 quadrupole time-of-flight mass spectrometer equipped with an electrospray ion source (Waters, Milford, MA) and analyzed with MassLynx software at the Korea Basic Science Institute. X-ray Crystallographic Data Collection and Structure Refinement. Suitable crystals of 1 and 3 were coated with paratone-N oil, and diffraction data were obtained at 100 K using synchrotron radiation (λ = 0.70000 Å), a ADSC Quantum-210 detector at 2D SMC, and a silicon (111) double-crystal monochromator at the Pohang Accelerator Laboratory. The PAL BL2D-SMDC program73 was used for data collection, and HKL3000sm74 was used for cell refinement, reduction, and absorption correction. Structures were solved by direct methods and refined by full-matrix least-squares calculation using the SHELX software package.75 Least-squares refinement of the structural model E

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

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Inorganic Chemistry (d, J = 6.9 Hz, 24H). 13C NMR (75 MHz, CD3OD/CD3NO2): δ 172.06, 153.41, 151.11, 140.44, 132.92, 130.19, 127.23, 123.43, 103.80, 98.79, 85.34, 83.10, 82.19, 74.96, 26.80, 22.10, 17.84. MS (ESI). Calcd for [3-3OTf]3+: m/z 1519.43. Found: m/z 1519.43. Calcd for [3-4OTf]4+: m/z 1102.33. Found: m/z 1102.33. Mp: 193−194 °C (dec). Anal. Calcd for C202H186Co2F24N8O40Ru8S8: C, 48.88; H, 3.75; N, 2.24. Found: C, 48.76; H, 3.80; N, 2.23.

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(5) Mukherjee, S.; Mukherjee, P. S. Template-free multicomponent coordination-driven self-assembly of Pd (II)/Pt (II) molecular cages. Chem. Commun. 2014, 50, 2239−2248. (6) Fujita, D.; Ueda, Y.; Sato, S.; Mizuno, N.; Kumasaka, T.; Fujita, M. Self-assembly of tetravalent Goldberg polyhedra from 144 small components. Nature 2016, 540, 563−566. (7) Olenyuk, B.; Whiteford, J. A.; Fechtenkötter, A.; Stang, P. J. Selfassembly of nanoscale cuboctahedra by coordination chemistry. Nature 1999, 398, 796−799. (8) Wang, M.; Wang, C.; Hao, X.-Q.; Li, X.; Vaughn, T. J.; Zhang, Y.-Y.; Yu, Y.; Li, Z.-Y.; Song, M.-P.; Yang, H.-B.; Li, X. From Trigonal Bipyramidal to Platonic Solids: Self-Assembly and Self-Sorting Study of Terpyridine-Based 3D Architectures. J. Am. Chem. Soc. 2014, 136, 10499−10507. (9) Seidel, S. R.; Stang, P. J. High-symmetry coordination cages via selfassembly. Acc. Chem. Res. 2002, 35, 972−983. (10) Huang, S.-L.; Hor, T. S. A.; Jin, G.-X. Metallacyclic assembly of interlocked superstructures. Coord. Chem. Rev. 2017, 333, 1−24. (11) Huang, S.-L.; Lin, Y.-J.; Hor, T. S. A.; Jin, G.-X. Cp* Rh-based heterometallic metallarectangles: size-dependent Borromean link structures and catalytic acyl transfer. J. Am. Chem. Soc. 2013, 135, 8125−8128. (12) Huang, S.-L.; Lin, Y.-L.; Li, Z.-H.; Jin, G.-X. Self-Assembly of Molecular Borromean Rings from Bimetallic Coordination Rectangles. Angew. Chem., Int. Ed. 2014, 53, 11218−11222. (13) Zhang, L.; Lin, L.; Liu, D.; Lin, Y.-J.; Li, Z.-H.; Jin, G.-X. Stacking interactions induced selective conformation of discrete aromatic arrays and Borromean rings. J. Am. Chem. Soc. 2017, 139, 1653−1660. (14) Samanta, D.; Mukherjee, P. S. Sunlight-induced covalent marriage of two triply interlocked Pd6 cages and their facile thermal separation. J. Am. Chem. Soc. 2014, 136, 17006−17009. (15) Cook, T. R.; Vajpayee, V.; Lee, M. H.; Stang, P. J.; Chi, K.-W. Biomedical and biochemical applications of self-assembled metallacycles and metallacages. Acc. Chem. Res. 2013, 46, 2464−2474. (16) Therrien, B. Biologically relevant arene ruthenium metallaassemblies. CrystEngComm 2015, 17, 484−491. (17) Saha, M. L.; Yan, X.; Stang, P. J. Photophysical properties of organoplatinum(II) compounds and derived self-assembled metallacycles and metallacages: fluorescence and its applications. Acc. Chem. Res. 2016, 49, 2527−2539. (18) Xu, L.; Wang, Y.-X.; Chen, L.-J.; Yang, H.-B. Construction of multiferrocenyl metallacycles and metallacages via coordination-driven self-assembly: from structure to functions. Chem. Soc. Rev. 2015, 44, 2148−2167. (19) Yan, X.; Cook, T. R.; Wang, P.; Huang, F.; Stang, P. J. Highly emissive platinum(II) metallacages. Nat. Chem. 2015, 7, 342−348. (20) Yoshizawa, M.; Klosterman, J. K.; Fujita, M. Functional molecular flasks: new properties and reactions within discrete, self-assembled hosts. Angew. Chem., Int. Ed. 2009, 48, 3418−3438. (21) Howlader, P.; Das, P.; Zangrando, E.; Mukherjee, P. S. Ureafunctionalized self-assembled molecular prism for heterogeneous catalysis in water. J. Am. Chem. Soc. 2016, 138, 1668−1676. (22) Das, P.; Kumar, A.; Howlader, P.; Mukherjee, P. S. A selfassembled trigonal prismatic molecular vessel for catalytic dehydration reactions in water. Chem. - Eur. J. 2017, 23, 12565−12574. (23) Howlader, P.; Mukherjee, P. S. Face and edge directed selfassembly of Pd12 tetrahedral nano-cages and their self-sorting. Chem. Sci. 2016, 7, 5893−5899. (24) Chen, L.-J.; Ren, Y.-Y.; Wu, N.-W.; Sun, B.; Ma, J.-Q.; Zhang, L.; Tan, H.; Liu, M.; Li, X.; Yang, H.-B. Hierarchical self-assembly of discrete organoplatinum(II) metallacycles with polysaccharide via electrostatic interactions and their application for heparin detection. J. Am. Chem. Soc. 2015, 137, 11725−11735. (25) Mishra, A.; Jung, H.; Lee, M. H.; Lah, M. S.; Chi, K.-W. Synthesis and characterization of self-assembled nanoscopic metallarectangles capable of binding fullerenes with size-selective responses. Inorg. Chem. 2013, 52, 8573−8578. (26) Shanmugaraju, S.; Vajpayee, V.; Lee, S.; Chi, K.-W.; Stang, P. J.; Mukherjee, P. S. Coordination-driven self-assembly of 2D-metal-

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.7b02653. 1 H, 13C, and DOSY NMR and ESI-MS data, a guest encapsulation study, and X-ray crystal structures and parameters of 1 and 3 (PDF) Accession Codes

CCDC 1581741−1581742 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

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AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Nem Singh: 0000-0003-2952-3385 Jatinder Singh: 0000-0003-3422-5796 Myoung Soo Lah: 0000-0001-9517-7519 Ki-Whan Chi: 0000-0002-7816-801X Author Contributions ‡

These authors contributed equally to the study.

Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS This work was supported by the Basic Science Research program through the National Research Foundation (NRF) of Korea (Grant 2016R1A2B4007433 to K.-W.C. and Grant 2014R1A1A2007897 to N.S.). Support from the Priority Research Centers program (2009-0093818) through the NRF is also appreciated. This research was also supported by the Korea Basic Science Institute under the R&D program (D37700) supervised by the Ministry of Science and ICT. XRD experiments using synchrotron radiation were performed at the Pohang Accelerator Laboratory.

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REFERENCES

(1) Chakrabarty, R.; Mukherjee, P. S.; Stang, P. J. Supramolecular coordination: self-assembly of finite two-and three-dimensional ensembles. Chem. Rev. 2011, 111, 6810−6918. (2) Northrop, B. H.; Zheng, Y.-R.; Chi, K.-W.; Stang, P. J. Selforganization in coordination-driven self-assembly. Acc. Chem. Res. 2009, 42, 1554−1563. (3) Harris, K.; Fujita, D.; Fujita, M. Giant hollow MnL2n spherical complexes: structure, functionalisation and applications. Chem. Commun. 2013, 49, 6703−6712. (4) Cook, T. R.; Stang, P. J. Recent developments in the preparation and chemistry of metallacycles and metallacages via coordination. Chem. Rev. 2015, 115, 7001−7045. F

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

Forum Article

Inorganic Chemistry lamacrocycles using a new carbazole-based dipyridyl donor: synthesis, characterization, and C60 binding study. Inorg. Chem. 2012, 51, 4817− 4823. (27) Wang, M.; Vajpayee, V.; Shanmugaraju, S.; Zheng, Y.-R.; Zhao, Z.; Kim, H.; Mukherjee, P. S.; Chi, K.-W.; Stang, P. J. Coordination-driven self-assembly of M3L2 trigonal cages from pre-organized metalloligands incorporating octahedral metal centers and fluorescent detection of nitroaromatics. Inorg. Chem. 2011, 50, 1506−1512. (28) Shanmugaraju, S.; Mukherjee, P. S. π-Electron rich small molecule sensors for the recognition of nitroaromatics. Chem. Commun. 2015, 51, 16014−16032. (29) Mishra, A.; Ravikumar, S.; Hong, S. H.; Kim, H.; Vajpayee, V.; Lee, H.; Ahn, B.; Wang, M.; Stang, P. J.; Chi, K.-W. DNA binding and unwinding by self-assembled supramolecular hetero-bimetallacycles. Organometallics 2011, 30, 6343−6348. (30) Gupta, G.; Das, A.; Park, K. C.; Tron, A.; Kim, H.; Mun, J.; Mandal, N.; Chi, K.-W.; Lee, C. Y. Self-assembled novel bodipy-based palladium supramolecules and their cellular localization. Inorg. Chem. 2017, 56, 4615−4621. (31) Li, S. J.; Huang, J. Y.; Cook, T. R.; Pollock, J. B.; Kim, H.; Chi, K.W.; Stang, P. J. Formation of [3] catenanes from 10 precursors via multicomponent coordination-driven self-assembly of metallarectangles. J. Am. Chem. Soc. 2013, 135, 2084−2087. (32) Schouwey, C.; Holstein, J. J.; Scopelliti, R.; Zhurov, K. O.; Nagornov, K. O.; Tsybin, Y. O.; Smart, O. S.; Bricogne, G.; Severin, K. Self-assembly of a giant molecular Solomon link from 30 subcomponents. Angew. Chem., Int. Ed. 2014, 53, 11261−11265. (33) Singh, N.; Kim, D.; Kim, D. H.; Kim, E.-H.; Kim, H.; Lah, M. S.; Chi, K.-W. Selective synthesis of iridium (III)-derived molecular Borromean rings, [2]catenane and ring-in-ring macrocycles via coordination-driven self-assembly. Dalton Trans. 2017, 46, 571−578. (34) Mishra, A.; Jeong, Y. J.; Jo, J.-H.; Kang, S. C.; Kim, H.; Chi, K.-W. Coordination-driven self-assembly and anticancer potency studies of arene−ruthenium-based molecular metalla-rectangles. Organometallics 2014, 33, 1144−1151. (35) An, S. S.; Chi, K.-W.; Kim, I.; Song, Y. H.; Singh, N.; Jeong, Y. J.; Kwon, J. E.; Kim, H.; Cho, Y. M.; Kang, S. C. Anticancer activities of selfassembled molecular bowls containing a phenanthrene-based donor and Ru(II) acceptors. Int. J. Nanomed. 2015, 10, 143−153. (36) Singh, N.; Jang, S.; Jo, J.-H.; Kim, D. H.; Park, D. W.; Kim, I.; Kim, H.; Kang, S. C.; Chi, K.-W. Coordination-driven self-assembly and anticancer potency studies of ruthenium−cobalt-based heterometallic rectangles. Chem. - Eur. J. 2016, 22, 16157−16164. (37) Bhowmick, S.; Jana, A.; Singh, K.; Gupta, P.; Gangrade, A.; Mandal, B. B.; Das, N. Coordination-driven self-assembly of ionic irregular hexagonal metallamacrocycles via an organometallic clip and their cytotoxicity potency. Inorg. Chem. 2017, DOI: 10.1021/ acs.inorgchem.7b01561. (38) Therrien, B.; Süss-Fink, G.; Govindaswamy, P.; Renfrew, A. K.; Dyson, P. J. The “Complex-in-a-complex” cations [(acac)2M-Ru6(piPrC6H4Me)6(tpt)2(dhbq)3]6+: a trojan horse for cancer cells. Angew. Chem., Int. Ed. 2008, 47, 3773−3776. (39) Schmitt, F.; Freudenreich, J.; Barry, N. P. E.; Juillerat-Jeanneret, L.; Süss-Fink, G.; Therrien, B. Organometallic cages as vehicles for intracellular release of photosensitizers. J. Am. Chem. Soc. 2012, 134, 754−757. (40) Garci, A.; Mbakidi, J.-P.; Chaleix, V.; Sol, V.; Orhan, E.; Therrien, B. Tunable arene ruthenium metallaprisms to transport, shield, and release porphin in cancer cells. Organometallics 2015, 34, 4138−4146. (41) Zheng, Y.-R.; Zhao, Z.; Kim, H.; Wang, M.; Ghosh, K.; Pollock, J. B.; Chi, K.-W.; Stang, P. J. Coordination-driven self-assembly of truncated tetrahedra capable of encapsulating 1,3,5-triphenylbenzene. Inorg. Chem. 2010, 49, 10238−10240. (42) Roy, B.; Ghosh, A. K.; Srivastava, S.; D’Silva, P.; Mukherjee, P. S. A Pd8 tetrafacial molecular barrel as carrier for water insoluble fluorophore. J. Am. Chem. Soc. 2015, 137, 11916−11919. (43) Singh, N.; Jo, J.-H.; Song, Y. H.; Kim, H.; Kim, D.; Lah, M. S.; Chi, K.-W. Coordination-driven self-assembly of an iridium-cornered

prismatic cage and encapsulation of three heteroguests in its large cavity. Chem. Commun. 2015, 51, 4492−4495. (44) Harris, K.; Fujita, D.; Fujita, M. Giant hollow MnL2n spherical complexes: structure, functionalisation and applications. Chem. Commun. 2013, 49, 6703−6712. (45) Wang, W.; Wang, Y. X.; Yang, H.-B. Supramolecular transformations within discrete coordination-driven supramolecular architectures. Chem. Soc. Rev. 2016, 45, 2656−2693. (46) Chen, L. J.; Yang, H.-B.; Shionoya, M. Chiral metallosupramolecular architectures. Chem. Soc. Rev. 2017, 46, 2555−2576. (47) Bar, A. K.; Mohapatra, S.; Zangrando, E.; Mukherjee, P. S. A series of trifacial pd6 molecular barrels with porphyrin walls. Chem. - Eur. J. 2012, 18, 9571−9579. (48) Bivaud, S.; Balandier, J.-Y.; Chas, M.; Allain, M.; Goeb, S.; Salle, M. A metal-directed self-assembled electroactive cage with bis(pyrrolo) tetrathiafulvalene (BPTTF) side walls. J. Am. Chem. Soc. 2012, 134, 11968−11970. (49) Ajibola Adeyemo, A.; Shettar, A.; Bhat, I. A.; Kondaiah, P.; Mukherjee, P. S. self-assembly of discrete ruii8 molecular cages and their in vitro anticancer activity. Inorg. Chem. 2017, 56, 608−617. (50) Bhat, I. A.; Jain, R.; Siddiqui, M. M.; Saini, D. K.; Mukherjee, P. S. Water-soluble Pd8L4 self-assembled molecular barrel as an aqueous carrier for hydrophobic curcumin. Inorg. Chem. 2017, 56, 5352−5360. (51) Yamanoi, Y.; Sakamoto, Y.; Kusukawa, T.; Fujita, M.; Sakamoto, S.; Yamaguchi, K. Dynamic assembly of coordination boxes from (en)Pd(II) unit and a rectangular panel-like ligand:- NMR, CSI-MS, and X-ray Studies. J. Am. Chem. Soc. 2001, 123, 980−881. (52) Cecot, G.; Marmier, M.; Geremia, S.; De Zorzi, R.; Vologzhanina, A. V.; Pattison, P.; Solari, E.; Fadaei Tirani, F.; Scopelliti, R.; Severin, K. The intricate structural chemistry of MII2nLn-type assemblies. J. Am. Chem. Soc. 2017, 139, 8371−8381. (53) Bar, A. K.; Chakrabarty, R.; Mostafa, G.; Mukherjee, P. S. Selfassembly of a nanoscopic Pt12Fe12 heterometallic open molecular box containing six porphyrin walls. Angew. Chem., Int. Ed. 2008, 47, 8455− 8459. (54) Yang, J.; Bhadbhade, M.; Donald, W. A.; Iranmanesh, H.; Moore, E. G.; Yan, H.; Beves, J. E. Self-assembled supramolecular cages containing ruthenium(II) polypyridyl complexes. Chem. Commun. 2015, 51, 4465−4468. (55) Caskey, D. C.; Yamamoto, T.; Addicott, C.; Shoemaker, R. K.; Vacek, J.; Hawkridge, A. M.; Muddiman, D. C.; Kottas, G. S.; Michl, J.; Stang, P. J. Coordination-driven face-directed self-assembly of trigonal prisms. face-based conformational chirality. J. Am. Chem. Soc. 2008, 130, 7620−7628. (56) Vacek, J.; Caskey, D. C.; Horinek, D.; Shoemaker, R. K.; Stang, P. J.; Michl, J. Pyridine ligand rotation in self-assembled trigonal prisms. Evidence for intracage solvent vapor bubbles. J. Am. Chem. Soc. 2008, 130, 7629−7638. (57) Yuan, Q.-H.; Yan, C.-J.; Yan, H.-J.; Wan, L.-J.; Northrop, B. H.; Jude, H.; Stang, P. J. Scanning tunneling microscopy investigation of a supramolecular self-assembled three-dimensional chiral prism on a Au(111) surface. J. Am. Chem. Soc. 2008, 130, 8878−8879. (58) Kumar, D.; Deb, M.; Singh, J.; Singh, N.; Keshav, K.; Elias, A. J. Chemistry of the highly stable hindered cobalt sandwich compound (η5Cp)Co(η4-C4Ph4) and its derivatives. Coord. Chem. Rev. 2016, 306, 115−170. (59) Johannessen, S. C.; Brisbois, R. G.; Fischer, J. P.; Grieco, P. A.; Counterman, A. E.; Clemmer, D. E. A Nano-Scale Barrel and Cube:Transition Metal-Mediated Self-Assembly of CpCoCb-Derived Ligand Scaffolds. J. Am. Chem. Soc. 2001, 123, 3818−3819. (60) Givelet, C. C.; Dron, P. I.; Wen, J.; Magnera, T. F.; Zamadar, M.; Č épe, K.; Fujiwara, H.; Shi, Y.; Tuchband, M. R.; Clark, N.; Zbořil, R.; Michl, J. Challenges in the structure determination of self-assembled metallacages: what do cage cavities contain, internal vapor bubbles or solvent and/or counter ions? J. Am. Chem. Soc. 2016, 138, 6676−6687. (61) Ryu, J. Y.; Park, Y. J.; Park, H. R.; Saha, M. L.; Stang, P. J.; Lee, J. Ruthenium-cobalt bimetallic supramolecular cages via a less symmetric tetrapyridyl metalloligand and the effect of spacer units. J. Am. Chem. Soc. 2015, 137, 13018−13023. G

DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX

Forum Article

Inorganic Chemistry (62) Ryu, J. Y.; Wi, E. H.; Pait, M.; Lee, S.; Stang, P. J.; Lee, J. Unique ruthenium bimetallic supramolecular cages from C4-symmetric tetrapyridyl metalloligands. Inorg. Chem. 2017, 56, 5471−5477. (63) Lee, H.; Elumalai, P.; Singh, N.; Kim, H.; Lee, S. U.; Chi, K.-W. Selective synthesis of ruthenium (II) metalla [2] catenane via solvent and guest-dependent self-assembly. J. Am. Chem. Soc. 2015, 137, 4674− 4677. (64) Jo, J. H.; Singh, N.; Kim, D.; Cho, S. M.; Mishra, A.; Kim, H.; Kang, S. C.; Chi, K.-W. Coordination-driven self-assembly using ditopic pyridyl−pyrazolyl donor and p-cymene Ru (II) Acceptors: [2]Catenane synthesis and anticancer activities. Inorg. Chem. 2017, 56, 8430−8438. (65) Song, Y. H.; Singh, N.; Jung, J.; Kim, H.; Kim, E.-H.; Cheong, H.K.; Kim, Y.; Chi, K.-W. Template-free synthesis of a molecular Solomon link by two-component self-assembly. Angew. Chem., Int. Ed. 2016, 55, 2007−2011. (66) Vajpayee, V.; Song, Y. H.; Cook, T. R.; Kim, H.; Lee, Y.; Stang, P. J.; Chi, K.-W. A unique non-catenane interlocked self-assembled supramolecular architecture and its photophysical properties. J. Am. Chem. Soc. 2011, 133, 19646−19649. (67) Kim, T.; Singh, N.; Oh, J.; Kim, E.-H.; Jung, J.; Kim, H.; Chi, K.-W. Selective synthesis of molecular borromean rings: engineering of supramolecular topology via coordination-driven self-assembly. J. Am. Chem. Soc. 2016, 138, 8368−6371. (68) Mishra, A.; Dubey, A.; Min, J. W.; Kim, H.; Stang, P. J.; Chi, K.-W. Molecular self-assembly of arene-Ru based interlocked catenane metalla-cages. Chem. Commun. 2014, 50, 7542−7544. (69) Barry, N. P.; Furrer, J.; Therrien, B. In- and out-of-cavity interactions by modulating the size of ruthenium metallarectangles. Helv. Chim. Acta 2010, 93, 1313−1328. (70) Yan, H.; Suss-Fink, G.; Neels, A.; Stoeckli-Evans, H. Mono-, diand tetra-nuclear p-cymeneruthenium complexes containing oxalato ligands. J. Chem. Soc., Dalton Trans. 1997, 4345−4350. (71) Bertrand, G.; Tortech, L.; Fichou, D.; Malacria, M.; Aubert, C.; Gandon, V. An improved protocol for the synthesis of [(η4-C4R4)Co(η5C5H5)] complexes. Organometallics 2012, 31, 126−132. (72) Stang, P. J.; Cao, D. H.; saito, S.; Arif, A. M. Self-aassembly of cationic, tetranuclear, Pt (II) and Pd (II) macrocyclic squares. X-ray crystal structure of [Pt2+ (dppp)(4, 4′-bipyridyl). cntdot. 2-OSO2CF3]4. J. Am. Chem. Soc. 1995, 117, 6273−6283. (73) Shin, J. W.; Eom, K.; Moon, D. BL2D-SMC, the supramolecular crystallography beamline at the Pohang Light Source II, Korea. J. Synchrotron Radiat. 2016, 23, 369−373. (74) Otwinowski, Z.; Minor, W. Processing of X-ray diffraction data collected in oscillation mode. In Methods in Enzymology; Carter, C. W., Jr., Sweet, R. M., Eds.; Academic Press: New York, 1997; Vol. 276, Part A, pp 307−326. (75) SHELX program: Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 3−8. (76) PLATON program: Spek, A. L. PLATON SQUEEZE: a tool for the calculation of the disordered solvent contribution to the calculated structure factors. Acta Crystallogr., Sect. C: Struct. Chem. 2015, 71, 9−18.

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DOI: 10.1021/acs.inorgchem.7b02653 Inorg. Chem. XXXX, XXX, XXX−XXX