# Fileset

[d3ra06526j.pdf](https://mdr.nims.go.jp/filesets/b3f14dc0-075e-40f8-b3b2-3110865f671c/download)

## Creator

[Peifeng Mei](https://orcid.org/0000-0002-4128-5685), Hirofumi Morimoto, Yuta Okada, [Kyohei Matsuo](https://orcid.org/0000-0002-2472-9459), [Hironobu Hayashi](https://orcid.org/0000-0002-7872-3052), [Akinori Saeki](https://orcid.org/0000-0001-7429-2200), [Hiroko Yamada](https://orcid.org/0000-0002-2138-5902), [Naoki Aratani](https://orcid.org/0000-0002-3181-6526)

## Rights



## Other metadata

[Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the crystals](https://mdr.nims.go.jp/datasets/552b0960-d502-410d-9bcf-979667be7f2d)

## Fulltext

Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the crystalsRSC AdvancesPAPEROpen Access Article. Published on 14 November 2023. Downloaded on 12/22/2023 1:16:27 AM.  This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.View Article OnlineView Journal  | View IssueComplexation staDivision of Materials Science, Nara Instit8916-5 Takayama-cho, Ikoma, 630-0192, JabDepartment of Applied Chemistry, Graduate2-1 Yamadaoka, Suita, 565-0871, Japan† Electronic supplementary informationprocedures and additional spectroscopicrystallographic data in CIF or ohttps://doi.org/10.1039/d3ra06526j‡ . Current address: College of ChemistUniversity, Beijing 100871, People's Repu§ . Current address: Institute for ChemicaUji, Kyoto 611-0011, Japan.{ . Current address: Center for Basic ReseMaterials Science (NIMS), 1-2-1 Sengen, TCite this: RSC Adv., 2023, 13, 33459Received 25th September 2023Accepted 7th November 2023DOI: 10.1039/d3ra06526jrsc.li/rsc-advances© 2023 The Author(s). Published byudy of a 1,3-phenylene-bridgedcyclic hexa-naphthalene with fullerenes C60 andC70 in solution and 1D-alignment of fullerenes inthe crystals†Peifeng Mei, ‡a Hirofumi Morimoto,a Yuta Okada,a Kyohei Matsuo, §aHironobu Hayashi, {a Akinori Saeki, b Hiroko Yamada §*aand Naoki Aratani *aTo investigate the host ability of a simple macrocycle, 1,3-phenylene-bridged naphthalene hexamerN6, weevaluated the complexation ofN6with fullerenes in toluene and in the crystals. The complexes in the solid-state demonstrate the one-dimensional alignment of fullerenes. The single-crystals of the C60@N6composite have semiconductive properties revealed by photoconductivity measurements.IntroductionMacrocyclic arenes constitute an important class of shape-persistent host molecules.1 This system features structuralrigidness, interesting optoelectronic properties, self-assemblingbehavior, and host–guest chemistry.2 In many cases, they forma large cavity inside to be used for fullerene recognition.3,4Naphthalene is one of the simplest polycyclic aromatic hydro-carbons (PAHs) with a rigid p-plane, which has been incorpo-rated into cycloarylenes.5–9 We reported a macrocyclic arene,1,3-phenylene-bridged cyclic naphthalene hexamer N6, thatcould be synthesized by a straightforward one-pot Suzuki–Miyaura reaction (Fig. 1).10 The crystal structure showed that theN6 had a symmetric hexagonal structure and a large cavity (d =ca. 15 Å). This unique structural characteristic allows N6 to bindthe spherical molecule C60 by forming a one-dimensional (1D)-alignment in the solid-state.10Here, to examine the effects of a variation in the size andshape of fullerenes,11 we investigated the host–guest interac-tions between N6 and spherical C60 and ellipsoidal C70 using1Hute of Science and Technology (NAIST),pan. E-mail: aratani@ms.naist.jpSchool of Engineering, Osaka University,(ESI) available: Detailed experimentalc data. CCDC: 2296635. For ESI andther electronic format see DOI:ry and Molecular Engineering, Pekingblic of China.l Research, Kyoto University, Gokasho,arch on Materials, National Institute forsukuba, Ibaraki 305-0047, Japan.the Royal Society of ChemistryNMR spectroscopy in solution and single-crystal X-ray diffrac-tion analysis in the solid state. Especially, we could determinethe association constants and stoichiometry of the complexa-tion fullerene@N6 in solutions, for the rst time, based on thestatistical methodology.Results and discussionComplexation analysis in solutionIn our previous report,10 we could not observe the formation ofthe complexes of N6 with C60 in chloroform due to the lowsolubility of C60. In the present study, we analyzed complexationof N6 in toluene as a better solvent for fullerenes. Recently, it isnoticed that Job's plot is inappropriate for estimating stoichi-ometries in the presence of more than one complex.11 There-fore, we attempted titration experiments with three differenthost–guest association models; 1 : 1, 1 : 2 and 2 : 1Fig. 1 Structures of a cyclic naphthalene hexamer N6, and fullerenesC60 and C70.RSC Adv., 2023, 13, 33459–33462 | 33459http://crossmark.crossref.org/dialog/?doi=10.1039/d3ra06526j&domain=pdf&date_stamp=2023-11-14http://orcid.org/0000-0002-4128-5685http://orcid.org/0000-0002-2472-9459http://orcid.org/0000-0002-7872-3052http://orcid.org/0000-0001-7429-2200http://orcid.org/0000-0002-2138-5902http://orcid.org/0000-0002-3181-6526https://doi.org/10.1039/d3ra06526jhttp://creativecommons.org/licenses/by-nc/3.0/http://creativecommons.org/licenses/by-nc/3.0/https://doi.org/10.1039/d3ra06526jhttps://pubs.rsc.org/en/journals/journal/RAhttps://pubs.rsc.org/en/journals/journal/RA?issueid=RA013047Fig. 3 (a) The chemical shift changes of inside proton resonanceobserved in 1H NMR titration of N6 with C70 in toluene-d8. ([N6] : [C70]= 10 : 0 to 1 : 9, the total concentration was 0.4 mM, 600 MHz, 298 K)(b) curve-fitting obtained by using the 2 : 1 binding model.RSC Advances PaperOpen Access Article. Published on 14 November 2023. Downloaded on 12/22/2023 1:16:27 AM.  This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.View Article Onlinecomplexation.12 Solutions of N6 (0.4 mM) and C60 (0.4 mM) intoluene-d8 were mixed in different ratios from 10 : 0 to 1 : 9 toprepare 10 samples. As an example, the chemical shi of theproton Ha in Fig. 1 was illustrated: the chemical shi originallyobserved at 7.64 ppm was shied to down-eld at 7.88 ppm dueto the host–guest interactions (Fig. 2a). The spectral features areanalogous to those of other naphthalene-C60 supramolecularsystems.13 This guest-binding proles (the initial data points:7.64, 7.53 and 7.40 ppm, 10 samples, total data points N = 30)were analyzed with the curve-tting for 1 : 1, 1 : 2 and 2 : 1binding systems (Fig. S2 and Table S1†).12 All the tted curvesagreed with the observed chemical shi changes. It is difficultto compare the tted curves of these models quantitatively sofurther analysis wasmade by investigation of the goodness-of-t(GOF). To evaluate the GOF of these models, Akaike's infor-mation criterion (AIC) statistics were applied according to therecent exercise to a similar binding system.14The AIC values are summarized in Table S1.† Based on thequantitative GOF analysis given by AIC calculation, the 2 : 1additive model is themost preferred (Fig. 2b).15 We obtained K11= 1.69 (±0.06) × 104 M−1 and K21 = 4.54 (±0.42) × 102 M−1 forthe rst and second complexation, respectively. The smaller K21value than K11 indicates that 1 : 1 complex is dominant insolution and 2 : 1 complex becomes coexistent when theconcentration of the host is high (Fig. S3†).15Previously we obtained the crystal structure of the complex ofN6 and C60, which allowed us to precisely determine the 1 : 1stoichiometry of this complex in the solid state (CCDC 1838834for N6, 1838835 for C60@N6).10 The crystallographic analysisconrmed the p-stacking between N6 and encapsulated C60.The dihedral angles of the facing naphthalene moieties vary tomaximize the interactions between the N6 and C60: upon thecomplexation, the dihedral angles became slightly wider fromthe energy minimized structure. The closest distance betweenthe C60 and naphthalene is 3.32 Å in the range of p-stacking.Then, we performed the titration between N6 and C70. Theformation of the N6–C70 complex in toluene-d8 was clearlysuggested using the 1H NMR (Fig. 3a). A curve-tting simulationof guest-binding prole also supported a 2 : 1 model (Fig. S5 andTable S2†). We obtained K11 = 2.52 (±0.22)× 104 M−1 and K21 =2.12 (±0.80) × 102 M−1 for the complexation (Fig. 3b). Theestimated K11 binding constant was 1.5 times larger than thatwith C60, inevitably due to the ellipsoidal shape of C70.Fig. 2 (a) The chemical shift changes of inside proton resonanceobserved in 1H NMR titration of N6with C60 in toluene-d8. ([N6] : [C60]= 10 : 0 to 1 : 9, the total concentration was 0.4 mM, 600 MHz, 298 K)(b) curve-fitting obtained by using the 2 : 1 binding model.33460 | RSC Adv., 2023, 13, 33459–33462Interestingly, the peak of N6 at 8.38 ppm assigned to Hbexhibited down-eld shi upon the addition of C60, while itshowed up-eld shi upon the addition of C70 (Fig. S7†). Thepeak at 7.53 ppm assigned to Hc similarly exhibited oppositepeak shis due to the addition of C60 and C70. These resultsillustrate that the angles between naphthalene and phenylenerespond to the C60 and C70 encapsulation with smaller andlarger sizes, respectively.Single-crystal X-ray analysisFortunately, we obtained the composite structure of N6–C70 bysingle-crystal X-ray diffraction analysis despite low resolution(>1.0 Å) due to very weak diffraction at the high q angle (Fig. 4).kSingle-crystals of N6–C70 composite were obtained by vapordiffusion of MeOH into a chlorobenzene solution. C70 in thecrystal is nicely captured within the cavity made by N6 withintermolecular distances in the range of 3.2–3.4 Å. Closerinspection of the crystal structure revealed that N6 keeps a 1 : 1complex with C70 similar to N6–C60 with the dihedral angles ofnaphthalene toward phenylene (51° and 72°). The fullerenemoiety occupied at the special position rened by applyingappropriate instructions. As shown in Fig. 4c, the complex alsoconsequently forms the directly-contacting one-dimensionalC70 array along the crystallographic a-axis. The long-axis ofthe C70 is tilted to the alignment direction by 33°, which is ex-pected to increase the contact area between two fullerenes andthus to increase the interaction strengths. The closest C–Cdistance between fullerenes in the array is 4.1 Å, suggesting thelarger electronic interaction between fullerenes than that in theN6–C60 composite (4.4 Å). In addition, the C–H/p interactionsbetween the hydrogen atoms of the naphthalene units and theC70 also contribute to the stabilization of the N6–C70 assembly.Photoconductivity measurementsThe structures of N6–C60 and N6–C70 are expected to have largeintermolecular orbital couplings. To discuss charge transportk Crystallographic data for C70@N6: C96H60 C70 C6H5Cl, Mw = 2166.69, triclinic,space group P�1 (#2), a = 11.75(4), b = 14.98(5), c = 15.88(5) Å a = 106.46(3),b = 101.62(3), g = 98.45(3)°, V = 2563(14) Å3, T = 103(2) K, Z = 1, reectionsmeasured 5549, 4553 unique. The nal R1 was 0.1092 (I > 2s(I)), and the nalwR on F2 was 0.4205 (all data), GOF = 1.084. CCDC: 2296635© 2023 The Author(s). Published by the Royal Society of Chemistryhttp://creativecommons.org/licenses/by-nc/3.0/http://creativecommons.org/licenses/by-nc/3.0/https://doi.org/10.1039/d3ra06526jFig. 4 X-ray structure of the N6–C70 1 : 1 complex, ORTEP drawingfrom (a) the side view and (b) top view with thermal ellipsoids scaled at25% probability. Disordered molecules are omitted for clarity. (c) Acolumnar array of N6–C70 along the a-axis. For clarity, C70 is shown asa space-filling model.Fig. 5 FP-TRMC profile of the single-crystals (C60@N6$PhCl) recor-ded at an excitation wavelength of 355 nmwith a photon density of 9.1×1015 photons per cm−2.Paper RSC AdvancesOpen Access Article. Published on 14 November 2023. Downloaded on 12/22/2023 1:16:27 AM.  This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.View Article Onlineproperty in detail, the charge transfer integrals of the HOMOs(Vhole) and LUMOs (Velectron) between the neighbouring C60 andC70 pairs were calculated based on the crystal structures usingADF program16 (Fig. S9†). Along the crystallographic a-axis, theVhole and Velectron values for C60 pairs were calculated to be 3.1and 3.0 meV, respectively. On the other hand, the Vhole andVelectron values for C70 pairs were 10.4 and 15.8 meV, respec-tively, higher than those of C60. With these expecting charge–transport properties in mind, we conducted ash-photolysistime-resolved microwave conductivity (FP-TRMC) measure-ments of C60@N6. This electrodeless method allows for evalu-ating short-range (∼10 nm) transient conductivities ofmaterials.17 With a 355 nm laser pulse at 25 °C, the pseudo-conductivity (fSmmax in cm2 V−1 s−1 in which f is thequantum efficiency of charge generation and Smmax is the sum© 2023 The Author(s). Published by the Royal Society of Chemistryof hole and electron mobilities) of N6–C60 exhibited fSmmax =1.3 × 10−4 cm2 V−1 s−1 (Fig. 5). This value is comparable toPC61BM18 and other conjugated molecules.19 Unfortunately, forC70@N6 which was expected to exhibit better charge mobilitiesthan N6–C60, we were unable to prepare single crystals of goodenough quantity to measure the FP-TRMC.ConclusionsIn summary, we present the molecular host N6 can bind thefullerenes C60 and C70 in solution and in the solid-state. TheNMR titration experiments and curve-tting suggest that thebinding prole between N6 and fullerenes analyzed by 2 : 1model was most likelihood with binding constants of K11 = 1.69(±0.06) × 104 M−1 and K21 = 4.54 (±0.42) × 102 M−1 forC60@N6 and K11 = 2.52 (±0.22) × 104 M−1 and K21 = 2.12(±0.80) × 102 M−1 for C70@N6. In the solid-state, on the otherhand, both N6–C60 and N6–C70 composites show 1 : 1 complexand make the 1D arrays of fullerenes with the aid of the N6agent as conrmed by the single-crystal X-ray analysis. Amongthese, N6–C60 exhibited the moderate fSmmax = 1.3 × 10−4 cm2V−1 s−1 by FP-TRMC. We are currently investigating the host–guest chemistry of N6 with larger fullerenes, expecting it toexhibit different selectivity and affinity.Author contributionsThe manuscript was written through contributions of allauthors. All authors have given approval to the nal version ofthe manuscript.Conflicts of interestThere are no conicts to declare.AcknowledgementsThis work was partly supported by Grants-in-Aid for ScienticResearch (No. JP20H02816 (HH), JP20H00379 (HY), JP20H05833(HY), JP22K19067, and JP23H01787 (NA), JP22K05255 (KM), andJP20H05836 (AS), and JST, PRESTO (No. JPMJPR21AC (HH)).RSC Adv., 2023, 13, 33459–33462 | 33461http://creativecommons.org/licenses/by-nc/3.0/http://creativecommons.org/licenses/by-nc/3.0/https://doi.org/10.1039/d3ra06526jRSC Advances PaperOpen Access Article. Published on 14 November 2023. Downloaded on 12/22/2023 1:16:27 AM.  This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.View Article OnlineHM thanks University Fellowships for the Creation of Innova-tion in Science and Technology. We acknowledge Dr MitsuakiYamauchi (Kyoto University) for helpful discussions. This workwas partially supported by ISHIZUE 2023 of Kyoto University.Notes and references1 S. E. Lewis, Chem. Soc. Rev., 2015, 44, 2221–2304; Y. Segawa,H. Ito and K. Itami, Nat. Rev. Mater., 2016, 1, 15002;M. A. Majewski and M. Stępień, Angew. Chem., Int. Ed.,2019, 58, 86–116.2 K. Yazaki, L. Catti and M. Yoshizawa, Chem. Commun., 2018,54, 3195–3206; D. Lorbach, A. Keerthi, T. M. Figueira-Duarte,M. Baumgarten, M. Wagner and K. Müllen, Angew. Chem.,Int. Ed., 2016, 55, 418–421; S. Toyota and E. Tsurumaki,Chem.–Eur. J., 2019, 25, 6878–6890; M. Iyoda andH. Shimizu, Chem. Soc. Rev., 2015, 44, 6411–6424; X. Lu,S. Lee, Y. Hong, H. Phan, T. Y. Gopalakrishna, T. S. Herng,T. Tanaka, M. E. Sandoval-Salinas, W. Zeng, J. Ding,D. Casanova, A. Osuka, D. Kim and J. Wu, J. Am. Chem.Soc., 2017, 139, 13173–13183; Y. Yamamoto,K. Wakamatsu, T. Iwanaga, H. Sato and S. Toyota, Chem.–Asian J., 2016, 11, 1370–1375.3 D. Canevet, E. M. Pérez and N. Mart́ın, Angew. Chem., Int. Ed.,2011, 50, 9248–9259; Y. Yamamoto, E. Tsurumaki,K. Wakamatsu and S. Toyota, Angew. Chem., Int. Ed., 2018,57, 8199–8202; H. Chen, Z. Xia and Q. Miao, Chem. Sci.,2022, 13, 2280–2285.4 T. Iwamoto, Y. Watanabe, T. Sadahiro, T. Haino andS. Yamago, Angew. Chem., Int. Ed., 2011, 50, 8342–8344;H. Ueno, T. Nishihara, Y. Segawa and K. Itami, Angew.Chem., Int. Ed., 2015, 54, 3707–3711.5 V. Hensel, K. Lützow, J. Jakob, K. Gessler, W. Saenger andA. D. Schlüter, Angew. Chem., Int. Ed. Engl., 1997, 36, 2654–2656; V. Hensel and A. D. Schlüter, Chem.–Eur. J., 1999, 5,421–429.6 Z. Sun, P. Sarkar, T. Suenaga, S. Sato and H. Isobe, Angew.Chem., Int. Ed., 2015, 127, 12991–12995; S. E. Lewis, Chem.Soc. Rev., 2015, 44, 2221–2304.7 H. A. Staab and F. Binnig, Tetrahedron Lett., 1964, 5, 319–321.33462 | RSC Adv., 2023, 13, 33459–334628 J. Y. Xue, K. Ikemoto, N. Takahashi, T. Izumi, H. Taka,H. Kita, S. Sato and H. Isobe, J. Org. Chem., 2014, 79, 9735–9739 and the references are therein.9 H.-W. Jiang, S. Ham, N. Aratani, D. Kim and A. Osuka,Chem.–Eur. J., 2013, 19, 13328–13336; Y. Nakamura,N. Aratani and A. Osuka, Chem. Soc. Rev., 2007, 36, 831–845.10 P. Mei, A. Matsumoto, H. Hayashi, M. Suzuki, N. Aratani andH. Yamada, RSC Adv., 2018, 8, 20872–20876.11 P. Thordarson, Chem. Soc. Rev., 2011, 40, 1305–1323;D. B. Hibbert and P. Thordarson, Chem. Commun., 2016,52, 12792; F. Ulatowski, K. Dabrowa, T. Bałakier andJ. Jurczak, J. Org. Chem., 2016, 81, 1746.12 Bindt, http://supramolecular.org.13 S. Mizyed, M. Ashram, D. O. Miller and P. E. Georghiou, J.Chem. Soc., Perkin Trans. 2, 2001, 10, 1916–1919;X.-W. Chen, K.-Sh. Chu, R.-J. Wei, Z.-L. Qiu, C. Tang andY.-Z. Tan, Chem. Sci., 2022, 13, 1636–1640.14 K. Ikemoto, K. Takahashi, T. Ozawa and H. Isobe, Angew.Chem., Int. Ed., 2023, 62, e202219059.15 Even for a simple cycloparaphenylene (CPP) macrocycle, 1:1and 2:1 complexes of [10]CPP and C60/C70 were detected insolution. M. Freiberger, M. B. Minameyer, I. Solymosi,S. Frühwald, M. Krug, Y. Xu, A. Hirsch, T. Clark,D. M. Guldi, M. von Delius, K. Amsharov, A. Görling,M. E. Pérez-Ojeda and T. Drewello, Chem.–Eur. J., 2023, 29,e202203734.16 ADF2021, Scientic Computing & Modeling (SCM), Theoreti-calChemistry, Vrije Universiteit, Amsterdam, The Nether-lands,http://www.scm.com.17 A. Saeki, Y. Koizumi, T. Aida and S. Seki, Acc. Chem. Res.,2012, 45, 1193–1202.18 A. Baumann, T. J. Savenije, D. H. K. Murthy, M. Heeney,V. Dyakonov and C. Deibel, Adv. Funct. Mater., 2011, 21,1687–1692.19 H. Yokoi, Y. Hiraoka, S. Hiroto, D. Sakamaki, S. Seki andH. Shinokubo, Nat. Commun., 2015, 6, 8215; T. Okamoto,K. Nakahara, A. Saeki, S. Seki, J. H. Oh, H. B. Akkerman,Z. Bao and Y. Matsuo, Chem. Mater., 2011, 23, 1646–1649;J. Terao, Y. Tanaka, S. Tsuda, N. Kambe, M. Taniguchi,T. Kawai, A. Saeki and S. Seki, J. Am. Chem. Soc., 2009, 131,18046–18047.© 2023 The Author(s). Published by the Royal Society of Chemistryhttp://supramolecular.orghttp://www.scm.comhttp://creativecommons.org/licenses/by-nc/3.0/http://creativecommons.org/licenses/by-nc/3.0/https://doi.org/10.1039/d3ra06526j Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the... Complexation study of a 1,3-phenylene-bridged cyclic hexa-naphthalene with fullerenes C60 and C70 in solution and 1D-alignment of fullerenes in the...