Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Tada-aki Yamagishi and Albert M. Brouwer
Chemical Communications 2013 vol. 49(Issue 48) pp:5468-5470
Publication Date(Web):24 Apr 2013
DOI:10.1039/C3CC42612B
A [2]rotaxane has been constructed from a di-pyrene appended pillar[5]arene wheel, a pyridinium axle, and a perylene stopper. It shows efficient Förster resonance energy transfer from pyrene to perylene by formation of a mechanically interlocked [2]rotaxane.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Kae Masaki and Tada-aki Yamagishi
Chemical Communications 2013 vol. 49(Issue 38) pp:3952-3954
Publication Date(Web):26 Mar 2013
DOI:10.1039/C3CC41592A
We report the first synthesis of bridged pillararenes. Meso-form pillar[6]arenes were diastereo-selectively formed by bridging units of a per-hydroxylated pillar[6]arene in an alternating up-and-down manner with dialkyldichlorosilanes.
Co-reporter:Tomoki Ogoshi, Kumiko Yoshikoshi, Takamichi Aoki and Tada-aki Yamagishi
Chemical Communications 2013 vol. 49(Issue 78) pp:8785-8787
Publication Date(Web):05 Aug 2013
DOI:10.1039/C3CC44384A
We report a photo-reversible switching system between assembly and disassembly of a supramolecular polymer consisting of an azobenzene-bridged pillar[5]arene dimer.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Tomohiro Akutsu, Masanobu Naito and Tada-aki Yamagishi
Chemical Communications 2013 vol. 49(Issue 78) pp:8782-8784
Publication Date(Web):31 Jul 2013
DOI:10.1039/C3CC44672G
A planar-chiral pillar[5]arene derivative containing one π-conjugated unit was prepared. Chiroptical changes were observed upon addition of the achiral guest 1,4-dicyanobutane.
Co-reporter:Tomoki Ogoshi ;Tada-aki Yamagishi
European Journal of Organic Chemistry 2013 Volume 2013( Issue 15) pp:2961-2975
Publication Date(Web):
DOI:10.1002/ejoc.201300079
Abstract
In 2008 we reported a new class of macrocyclic hosts that we named “pillararenes”. To date, pillar[5]arenes and pillar[6]arenes, containing five and six repeating units, respectively, have been synthesized. Pillar[5]arenes and pillar[6]arenes can accommodate 10 and 12 substituent groups, respectively. The position-selective versatile functionalization of these substituents enables the preparation of various supramolecular assemblies. Here we discuss the synthesis and selective functionalization of pillararenes. We also discuss the use of the various pillararene derivatives as components of supramolecular assemblies such as sensors, a self-inclusion complex, supramolecular dimers, polymers, an alternating polymer consisting of pillar[5]arene and pillar[6]arene units, systems in which pillararene shuttles along an axle, rotaxanes, polyrotaxanes, and pillar[5]arene-based bulk-materials, as well as colloidal assembly of pillararenes, biomedical applications, and hybridization with inorganic materials.
Co-reporter:Tomoki Ogoshi ;Tada-aki Yamagishi
European Journal of Organic Chemistry 2013 Volume 2013( Issue 15) pp:
Publication Date(Web):
DOI:10.1002/ejoc.201390039
Co-reporter:Dr. Tomoki Ogoshi;Tomohiro Akutsu;Daiki Yamafuji;Takamichi Aoki ;Dr. Tada-aki Yamagishi
Angewandte Chemie International Edition 2013 Volume 52( Issue 31) pp:8111-8115
Publication Date(Web):
DOI:10.1002/anie.201302675
Co-reporter:Dr. Tomoki Ogoshi;Tomohiro Akutsu;Daiki Yamafuji;Takamichi Aoki ;Dr. Tada-aki Yamagishi
Angewandte Chemie 2013 Volume 125( Issue 31) pp:8269-8273
Publication Date(Web):
DOI:10.1002/ange.201302675
Co-reporter:Tomoki Ogoshi ; Ryohei Shiga ;Tada-aki Yamagishi
Journal of the American Chemical Society 2012 Volume 134(Issue 10) pp:4577-4580
Publication Date(Web):February 28, 2012
DOI:10.1021/ja300989n
A thermoresponsive macromolecule consisting of 10 outer triethylene oxide groups and a pillar[5]arene core was prepared. The macromolecule showed lower critical solution temperature behavior. Moreover, its clouding point can be reversibly tuned based on the addition of guest and host compounds; the clouding point increased upon addition of a guest didecylviologen salt and decreased when the competitive host cucurbit[7]uril was added.
Co-reporter:Tomoki Ogoshi ; Kanako Kida ;Tada-aki Yamagishi
Journal of the American Chemical Society 2012 Volume 134(Issue 49) pp:20146-20150
Publication Date(Web):November 19, 2012
DOI:10.1021/ja3091033
A new water-soluble thermoresponsive pillar[6]arene with triethylene oxide groups was synthesized. The pillar[6]arene showed lower critical solution temperature behavior in aqueous solution. Its clouding point was photoreversibly switched based on a photoresponsive host–guest system. The trans form of an azobenzene guest formed a stable 1:1 complex with the pillar[6]arene. Complexation increased the clouding point. Irradiation with UV light induced a conformation change for the azobenzene guest from the trans to cis form, and dethreading occurred because of a size mismatch between the cis form and the pillar[6]arene cavity. This dethreading decreased the clouding point. The photoresponsive host–guest system was reversible, and the clouding point could be switched by alternating irradiation with UV or visible light. We demonstrated photoresponsive reversible clear-to-turbid and turbid-to-clear transitions for the solution based on the reversible switching of the clouding point using the photosensitive host–guest system.
Co-reporter:Tomoki Ogoshi ; Takamichi Aoki ; Ryohei Shiga ; Ryo Iizuka ; Seita Ueda ; Kazuki Demachi ; Daiki Yamafuji ; Hitoshi Kayama ;Tada-aki Yamagishi
Journal of the American Chemical Society 2012 Volume 134(Issue 50) pp:20322-20325
Publication Date(Web):December 3, 2012
DOI:10.1021/ja310757p
We developed “cyclic host liquids (CHLs)” as a new type of solvent. The CHLs are a nonvolatile liquid over a wide temperature range, are biocompatible and recyclable, have high thermal stability, and are miscible with many organic solvents. Compared with typical complexation systems, the CHL system is extremely efficient for maintaining host–guest complexation because an additional solvent is not required. Based on the efficient host–guest complexation in the CHL system, we demonstrated synthesis of [2]rotaxanes in pillar[5]arene-based CHL. High yields were obtained for [2]rotaxanes capped by cationization (yield 91%) and Huisgen reaction (yield 88%) between the axle and the stopper components in the CHL system, while the association constants between the axles and wheels were quite low (10–15 M–1) in CDCl3. The CHL system provides a new powerful approach for synthesis of mechanically interlocked molecules (MIMs) even with unfavorable statistical combinations of host–guest complexes.
Co-reporter:Tomoki Ogoshi, Hitoshi Kayama, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chemical Science 2012 vol. 3(Issue 11) pp:3221-3226
Publication Date(Web):31 Jul 2012
DOI:10.1039/C2SC20982A
A highly selective multiple host–guest complexation system based on pillar[5]arene and pillar[6]arene is reported. A pyridinium cation moiety is included in the pillar[5]arene cavity, but hardly forms a stable host–guest complex with pillar[6]arene. A 1,4-diazabicyclo[2.2.2]octane cation moiety forms a host–guest complex with pillar[6]arene, but not with pillar[5]arene. A synthetic route to mono-reactive pillar[6]arene is also developed, enabling the synthesis of pillar[6]arene with a pyridinium cation group at a single position. Based on the highly selective multiple host–guest complexation system and mono-reactive pillar[6]arene, a supramolecular polymer with alternating pillar[5]arene and pillar[6]arene units is constructed.
Co-reporter:Tomoki Ogoshi, Naosuke Ueshima, Tada-aki Yamagishi, Yoshiyuki Toyota and Noriyoshi Matsumi
Chemical Communications 2012 vol. 48(Issue 29) pp:3536-3538
Publication Date(Web):15 Feb 2012
DOI:10.1039/C2CC30589E
A room-temperature ionic liquid containing macrocyclic compound pillar[5]arene in its core was synthesized. The ionic liquid showed high thermal stability, moderate ionic conductivity and solvent-free complexation ability with the guest tetracyanoethylene.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chemical Communications 2012 vol. 48(Issue 54) pp:6842-6844
Publication Date(Web):16 May 2012
DOI:10.1039/C2CC32865H
A [2]rotaxane constructed from a per-ethylated pillar[6]arene as a wheel and a pyridinium derivative as an axle was prepared. The wheel segment of the per-ethylated pillar[6]arene moved from one station to another along the axle as a result of thermal stimuli.
Co-reporter:Dr. Tomoki Ogoshi;Daiki Yamafuji;Takamichi Aoki;Keisuke Kitajima; Tada-aki Yamagishi;Yoshihiro Hayashi;Dr. Susumu Kawauchi
Chemistry - A European Journal 2012 Volume 18( Issue 24) pp:7493-7500
Publication Date(Web):
DOI:10.1002/chem.201200122
Abstract
Planar chiral [2]- and [3]rotaxanes constructed from pillar[5]arenes as wheels and pyridinium derivatives as axles were obtained in high yield using click reactions. The process of rotaxane formation was diastereoselective; the obtained [2]rotaxane was a racemic mixture consisting of (pS, pS, pS, pS, pS) and (pR, pR, pR, pR, pR) forms of the per-ethylated pillar[5]arene (C2) wheel, and other possible types of the [2]rotaxane did not form. Isolation of the enantiopure [2]rotaxanes with one axle through (pS, pS, pS, pS, pS)-C2 or (pR, pR, pR, pR, pR)-C2 wheels was accomplished. Furthermore, pillar[5]arene-based [3]rotaxane was successfully synthesized by attachment of two pseudo [2]rotaxanes onto a bifunctional linker. [3]Rotaxane formed in a 1:2:1 mixture with one axle threaded through two (pS, pS, pS, pS, pS)-C2, one (pS, pS, pS, pS, pS)-C2 and one (pR, pR, pR, pR, pR)-C2 (meso form), or two (pR, pR, pR, pR, pR)-C2 wheels. The [3]rotaxane enantiomers and the meso form were successfully isolated using appropriate chiral HPLC column chromatography. The procedure developed in this study is the starting point for the creation of pillar[5]arene-based interlocked molecules.
Co-reporter:Tomoki Ogoshi
Journal of Inclusion Phenomena and Macrocyclic Chemistry 2012 Volume 72( Issue 3-4) pp:247-262
Publication Date(Web):2012 April
DOI:10.1007/s10847-011-0027-2
In 2008, we reported a new class of macrocyclic hosts and named “Pillar[5]arenes”. They combine the advantages and aspects of traditional hosts and have a composition similar to those of typical calix[n]arenes. Pillar[5]arenes have repeating units connected by methylene bridges at the para-position, and thus they have a unique symmetrical pillar architecture differing from the basket-shaped structure of meta-bridged calix[n]arenes. Pillar[5]arenes show high functionality similar to cyclodextrins, and can capture electron accepting guest molecules within their cavity similarly to cucurbit[n]urils. In this review, the synthesis, structure, rotation, host–guest properties, planar chirality and functionality of pillar[5]arenes are discussed, along with pillar[5]arene-based supramolecular architectures and the challenges in synthesizing pillar[6]arenes.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Daisuke Kotera, Takamichi Aoki, Shuhei Fujinami, and Tada-aki Yamagishi
The Journal of Organic Chemistry 2012 Volume 77(Issue 24) pp:11146-11152
Publication Date(Web):December 3, 2012
DOI:10.1021/jo302283n
We report a new route for the selective synthesis of di- and tetrafunctionalized pillararenes via oxidation and reduction of the pillararene units. Hypervalent-iodine oxidation of perethylated pillar[5]arene afforded pillar[5]arene derivatives containing one benzoquinone unit and two benzoquinones at the A,B- and A,C-units. A pillar[6]arene derivative containing one benzoquinone unit was also synthesized. Reduction of the benzoquinone units yielded position-selective di- and tetrahydroxylated pillararene derivatives. This methodology avoids the generation of many constitutional isomers and overcomes the isolation problem of numerous constitutional isomers. From these hydroxylated pillararenes, Huisgen reaction-based clickable di- and tetraalkynylated pillar[5]arenes were prepared. Because of the highly selective and reactive nature of Huisgen alkyne–azide cycloaddition, these pillar[5]arenes can serve as key compounds for a large library of di- and tetrafunctionalized pillararenes. Based on these di- and tetrafunctionalized pillar[5]arenes as key compounds, fluorescent sensors were created by the modification of di- and tetrapyrene moieties via Huisgen-type click reactions.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Keisuke Kitajima and Tada-aki Yamagishi
Chemical Communications 2011 vol. 47(Issue 25) pp:7164-7166
Publication Date(Web):24 May 2011
DOI:10.1039/C1CC12333E
The first synthesis of a monohydroxy pillar[5]arene has been carried out, by controlling the de-O-methylation of per-methylated pillar[5]arene. Using monohydroxy pillar[5]arene as an intermediate, mono-guest-functionalized pillar[5]arene was prepared. It formed a self-inclusion complex in CDCl3 whereas in acetone-d6 dethreading of the guest moiety took place.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Keisuke Kitajima and Tada-aki Yamagishi
Chemical Communications 2011 vol. 47(Issue 37) pp:10290-10292
Publication Date(Web):22 Aug 2011
DOI:10.1039/C1CC14395F
A pillar[5]arene dimer was synthesized by linking a mono-hydroxylated pillar[5]arene with 1,4-bis(bromomethyl)benzene. The pillar[5]arene dimer formed stronger complexes with n-alkanes than did a monomeric pillar[5]arene.
Co-reporter:Tomoki Ogoshi, Ryohei Shiga, Masayoshi Hashizume and Tada-aki Yamagishi
Chemical Communications 2011 vol. 47(Issue 24) pp:6927-6929
Publication Date(Web):23 May 2011
DOI:10.1039/C1CC11864A
Introduction of bulky substituents such as benzyl and pyrenyl groups using click reactions inhibited or slowed the rotation of the units on the NMR chemical shift timescale. The perpyrenylated pillar[5]arene showed a thermally-responsive excimer emission, but a unit model of the perpyrenylated pillar[5]arene did not exhibit such a response.
Co-reporter:Tomoki Ogoshi, Keisuke Kitajima, Shuhei Fujinami and Tada-aki Yamagishi
Chemical Communications 2011 vol. 47(Issue 36) pp:10106-10108
Publication Date(Web):03 Aug 2011
DOI:10.1039/C1CC13546E
The reaction of 1,4-dimethoxybenzene and paraformaldehyde using AlBr3 yields multiple-deprotected pillar[5]arenes. A1/B2 di-deprotected pillar[5]arene can be isolated by silica gel chromatography and washing procedures. The X-ray structure and polymerization of the A1/B2 di-deprotected pillar[5]arene are reported.
Co-reporter:Tomoki Ogoshi, Takeshi Onodera, Tada-aki Yamagishi, Yoshiaki Nakamoto, Akihito Kagata, Noriyoshi Matsumi and Keigo Aoi
Polymer Journal 2011 43(4) pp:421-424
Publication Date(Web):February 16, 2011
DOI:10.1038/pj.2011.1
We report transparent ion conductive ionic liquid-phenol resin hybrids prepared by in situ polymerization/crosslinking of phenol monomer in ionic liquid. As ionic liquid, we used highly ion conductive ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([EMI][TFSA]). Simultaneous polymerization and crosslinking of phenol with paraformaldehyde in [EMI][TFSA] yielded a highly transparent film. From a field emission scanning electron microscope (FE-SEM) image at 5000 magnification, the transparent hybrid prepared by in situ method did not show phase separation at 5000 magnification. In addition, from the FE-SEM image of the transparent hybrid at high magnification ( × 60 000), phenol resin and [EMI][TFSA] were observed to be integrated at a scale of a few nanometers. The transparent hybrid containing 20 wt% phenol resin showed high thermal stability and ionic conductivity (1.0 × 10−3 S cm−1 at 30 °C), which is comparable to the pristine ionic liquid [EMI][TFSA].
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Takamichi Aoki, and Tada-aki Yamagishi
The Journal of Organic Chemistry 2011 Volume 76(Issue 22) pp:9497-9503
Publication Date(Web):October 17, 2011
DOI:10.1021/jo202040p
Photoswitching of the transformation between seconds and hours time-scales is demonstrated using the threading of per-hydroxylated pillar[5]arene onto the azobenzene-end of a viologen derivative. When the azobenzene moiety was in the trans form, the threading of per-hydroxylated pillar[5]arene quickly took place at 25 °C and could not be monitored directly. The exchange rate (k) and half-life time (t1/2) examined by 2D EXSY NMR spectroscopy were found to be 0.209 ± 0.013 s–1 and 3.33 ± 0.21 s, respectively. In contrast, the cis form of the azobenzene moiety required very long time (k = 2.14 ± 0.27 × 10–5 s–1, t1/2 = 9.13 ± 1.2 h) to thread per-hydroxylated pillar[5]arene at 25 °C. Photoisomerization from the trans to the cis form generated the following increment of free energy of activation at 25 °C: ΔGin‡ (cis form) – ΔGin‡ (trans form) = 22.8 ± 0.24 kJ mol–1, which led to the time-scale transformation. The tuning of the threading was also accomplished by heating/cooling: the rate constants increased on heating and decreased on cooling.
Co-reporter:Tomoki Ogoshi, Yuko Hasegawa, Takamichi Aoki, Yusuke Ishimori, Shinsuke Inagi, and Tada-aki Yamagishi
Macromolecules 2011 Volume 44(Issue 19) pp:7639-7644
Publication Date(Web):September 15, 2011
DOI:10.1021/ma2016979
We report on the reduction of polyaniline (PANI) by pillar[5]arene based on the formation of the poly(pseudorotaxane) structure. When pillar[5]arene was mixed with emeraldine base (EB) form of PANI, a blue solution color resulting from the EB form of PANI was diluted over time, and became completely colorless after 180 min. The FT-IR spectrum of the mixture of the EB form of PANI and pillar[5]arene displayed a new band at 1646 cm–1, which was assigned the C═O stretching band of benzoquinone. These results indicate that both oxidation of the hydroquinone units of pillar[5]arene and reduction of the EB form of PANI were induced by mixing the EB form of PANI and pillar[5]arene. Pillar[5]arene showed a stronger reducing ability than the unit model of hydroquinone. The ROE correlations between the methylene bridge protons of pillar[5]arene and the benzene protons of PANI indicated that the PANI chain was included into the pillar[5]arene cavity. Formation of the poly(pseudorotaxane) structure between PANI and pillar[5]arene was the main reason for the strong reducing ability of the EB form of PANI.
Co-reporter:Tomoki Ogoshi, Masayoshi Hashizume, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2010 vol. 46(Issue 21) pp:3708-3710
Publication Date(Web):13 Apr 2010
DOI:10.1039/C0CC00348D
Water-soluble pillar[5]arene was synthesized by the introduction of carboxylate anions at both upper and lower rims. When cationic viologen salt was mixed with the water-soluble pillar[5]arene in aqueous media, a very stable 1 ∶ 1 host–guest complex was formed.
Co-reporter:Tomoki Ogoshi, Keisuke Kitajima, Tada-aki Yamagishi and Yoshiaki Nakamoto
Organic Letters 2010 Volume 12(Issue 3) pp:636-638
Publication Date(Web):January 8, 2010
DOI:10.1021/ol902877w
A new nonsymmetric pillar[5]arene of ethoxymethoxypillar[5]arene (EMpillar[5]arene) has been synthesized. By 2D ROESY analysis of EMpillar[5]arene, the ethoxy and methoxy moieties were completely separated at the upper and lower rims, respectively. Moreover, by the variable-temperature 1H NMR measurements of EMpillar[5]arene, the rotational movement of phenolic units in EMpillar[5]arene was slow on the NMR time scale or did not occur.
Co-reporter:Tomoki Ogoshi, Yuto Ichihara, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2010 vol. 46(Issue 33) pp:6087-6089
Publication Date(Web):23 Jul 2010
DOI:10.1039/C0CC01644F
The preparation of a hybrid of graphene oxide and per-6-amino-β-cyclodextrin is reported. The hybrid formed a supramolecular graphene oxide polymer network upon addition of guest dimer.
Co-reporter:Tomoki Ogoshi, Yoko Nishida, Tada-aki Yamagishi and Yoshiaki Nakamoto
Polymer Chemistry 2010 vol. 1(Issue 2) pp:203-206
Publication Date(Web):16 Dec 2009
DOI:10.1039/B9PY00221A
We synthesized a novel alternating copolymer composed of calix[4] arene and calix[6]arene. Compared to the model compounds of calix[4]arene and calix[6]arene, the alternating copolymer strongly captured fluoranthene because of multipoint host–guest interactions between the calixarenes in the alternating copolymer and fluoranthene.
Co-reporter:Tomoki Ogoshi, Keisuke Kitajima, Takamichi Aoki, Tada-aki Yamagishi and Yoshiaki Nakamoto
The Journal of Physical Chemistry Letters 2010 Volume 1(Issue 5) pp:817-821
Publication Date(Web):February 5, 2010
DOI:10.1021/jz900437r
The rotation behavior of the phenolic units in pillar[5]arenes has been studied by means of the dynamic 1H NMR measurements. In acetone-d6, the individual conformers of pillar[5]arene were observed under −60 °C, indicating that the rotation movement was slow on the NMR time scale under −60 °C. In permethylated pillar[5]arene in acetone-d6, the peaks were not split even at −90 °C, strongly suggesting that the rotation movement was fast on the NMR time scale at −90 °C. This is due to the lack of the intramolecular hydrogen bond belt in permethylated pillar[5]arene. In the mixture of pillar[5]arene and viologen guest in acetone-d6, the split peaks were found at −30 °C and did not change under −60 °C. By formation of the host−guest complex between pillar[5]arene and viologen guest, the rotation movement was slow on the NMR time scale under −30 °C and almost stopped under −60 °C.Keywords (keywords): host−guest complex; intramolecular hydrogen bond belt; permethylated pillar[5]arene; pillar[5]arene; rotation; variable-temperature 1H NMR measurements;
Co-reporter:Tomoki Ogoshi, Yoko Nishida, Tada-aki Yamagishi and Yoshiaki Nakamoto
Macromolecules 2010 Volume 43(Issue 17) pp:7068-7072
Publication Date(Web):August 11, 2010
DOI:10.1021/ma101320z
New polyrotaxane composed of pillar[5]arene and viologen polymer was successfully prepared with extremely high yield by capping the chain ends with adamantyl moieties. Pillar[5]arene and viologen polymer are soluble in various solvents such as acetone, acetonitrile, methanol, DMF, and DMSO, while the polyrotaxane was soluble in DMF and DMSO and insoluble in the other organic solvents. Formation of inter-molecular hydrogen bonds between the OH moieties of pillar[5]arenes stabilized the structure and reduced the solubility. The polyrotaxane exhibited a thermally induced color change from yellow to violet. On heating, the inter-molecular hydrogen bond became weakened, and the shuttling motion of pillar[5]arenes on the polymer axis was fast. Thus, efficient electron transfer from the electron donors of pillar[5]arenes to the electron acceptor of viologen polymer occurred in the whole polymer chain and the radical cation species were stabilized.
Co-reporter:Tomoki Ogoshi, Masayoshi Hashizume, Tada-aki Yamagishi and Yoshiaki Nakamoto
Langmuir 2010 Volume 26(Issue 5) pp:3169-3173
Publication Date(Web):November 9, 2009
DOI:10.1021/la903103w
We report supramolecular assemblies of a β-cyclodextrin dimer linked at both ends of a fluorescent phenylethynylpyrene moiety (Py-β-CD dimer). The Py-β-CD dimer formed supramolecular associations in aqueous media due to the π−π stacking of the hydrophobic phenylethynylpyrene moiety. From tapping mode atomic force microscopy measurements, the Py-β-CD dimer formed wire-shaped assemblies in aqueous media. By adding sodium adamantane carboxylate to the supramolecular assemblies, the structural change to J-type assemblies was observed. In contrast, upon addition of the electron-deficient guest, the electron transfer from the electron rich phenylethynylpyrene moiety of the supramolecular assemblies to the electron-deficient guest took place.
Co-reporter:Tomoki Ogoshi, Yoko Nishida, Tada-aki Yamagishi and Yoshiaki Nakamoto
Macromolecules 2010 Volume 43(Issue 7) pp:3145-3147
Publication Date(Web):March 11, 2010
DOI:10.1021/ma100079g
Co-reporter:Tomoki Ogoshi, Kenji Umeda, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2009 (Issue 32) pp:4874-4876
Publication Date(Web):14 Jul 2009
DOI:10.1039/B907894K
Pillar[5]arene from modified phenylethynyl groups was prepared; since the repeating π-conjugated units were largely π-delocalized via the through-space within the cavity, it showed temperature- and solvent-responsive blue-green emission.
Co-reporter:Tomoki Ogoshi, Takayuki Saito, Tada-aki Yamagishi, Yoshiaki Nakamoto
Carbon 2009 Volume 47(Issue 1) pp:117-123
Publication Date(Web):January 2009
DOI:10.1016/j.carbon.2008.09.036
Hyperbranched phenolic polymer (HBP) was prepared by Lewis acid-catalyzed polycondensation of bifunctional phenolic monomer with trifunctional phenolic monomer. By choosing an appropriate Lewis acid, HBP was successfully obtained. By using physical adsorption of HBP on a single-walled carbon nanotube (SWCNT) surface, solubilization of SWCNTs was examined. SWCNTs were soluble with extended branches of HBP in N,N-dimethylformamide (DMF) solution, while they were insoluble in a linear phenolic polymer. In the presence of shrinking branches of HBP in tetrahydrofuran, SWCNTs were hardly soluble. Entanglements between extended branches of HBP and SWCNT in DMF solution resulted in high solubility of SWCNTs.
Co-reporter:Tomoki Ogoshi, Keisuke Kitajima, Kenji Umeda, Sachi Hiramitsu, Suguru Kanai, Shuhei Fujinami, Tada-aki Yamagishi, Yoshiaki Nakamoto
Tetrahedron 2009 65(51) pp: 10644-10649
Publication Date(Web):
DOI:10.1016/j.tet.2009.10.059
Co-reporter:Tomoki Ogoshi, Sachi Hiramitsu, Tada-aki Yamagishi and Yoshiaki Nakamoto
Macromolecules 2009 Volume 42(Issue 8) pp:3042-3047
Publication Date(Web):March 30, 2009
DOI:10.1021/ma900169j
We report on synthesis, association behavior, and application of six-arm star-shaped and tadpole-shaped amphiphilic polyoxazolines from triphenylene initiators. We synthesized two kinds of novel triphenylene initiators: 2,3,6,7,10,11-hexa(6-bromohexyloxy)triphenylene (initiator for star-shaped polyoxazoline) and 2-(6-bromohexyloxy)-3,6,7,10,11-pentahexyloxytriphenylene (initiator for tadpole-shaped polyoxazoline). Ring-opening cationic polymerization of 2-methyl-2-oxazoline from these initiators successfully produced star- and tadpole-shaped polyoxazolines. Both the star- and tadpole-shaped polyoxazolines formed supramolecular associations in aqueous media due to π−π stacking of hydrophobic triphenylene moiety. Critical micelle concentrations (CMCs) and amounts of π−π stacking of the star- and tadpole-shaped polyoxazolines in aqueous media were investigated by 1H NMR and fluorescence measurements. From tapping mode atomic force microscopy (TM-AFM) measurements, the star-shaped polyoxazolines formed straight columnar stacks due to π−π stacking of hydrophobic disklike core of triphenylene moiety and symmetric star-shaped structure. In contrast, crooked nanowires were observed in the tadpole-shaped polyoxazoline. Tadpole shape was asymmetric, and thus ordered π−π stacking of hydrophobic triphenylene moiety was suppressed. Moreover, by using the columnar stacks of the star-shaped polyoxazoline as a template, we successfully synthesized wire-assembled gold nanoparticles.
Co-reporter:Tomoki Ogoshi, Ayumi Inagaki, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2008 (Issue 19) pp:2245-2247
Publication Date(Web):12 Mar 2008
DOI:10.1039/B801546E
Single-walled carbon nanotubes (SWCNTs) were suspended in aqueous media with cucurbit[7]uril (CB7), while SWCNTs were insoluble with cucurbit[5]uril (CB5). Moreover, defection-selective solubilization of SWCNTs with CB7 was demonstrated.
Co-reporter:Tomoki Ogoshi, Mitsuhiro Ikeya, Tada-aki Yamagishi, Yoshiaki Nakamoto and Akira Harada
The Journal of Physical Chemistry C 2008 Volume 112(Issue 34) pp:13079-13083
Publication Date(Web):2017-2-22
DOI:10.1021/jp801455e
Solubilization of single-walled carbon nanotubes (SWNTs) by physical adsorption of cyclodextrins (CDs), guest molecules, and host−guest complexes was investigated. As guest compounds, sodium adamantanecarboxylate (AdCNa), sodium dodecylbenzenesulfonate (SDBS), sodium ursodeoxycholate (UdCNa), sodium ferrocenecarboxylate (FeCNa), and TritonX-405 were employed. As host compounds, α-, β-, and γ-cyclodextrins (α-, β-, and γ-CDs) were used. By using CDs as a solubilizing agent, SWNTs were insoluble in aqueous media. In the presence of AdCNa and FeCNa, solubility of SWNTs was dramatically increased by formation of host−guest complex with β- or γ-CDs. By using SDBS-CD complexes, solubility of SWNTs was also enhanced compared to only guest molecules. On the other hand, solubility of SWNTs was decreased by formation of host−guest complexes of UdCNa and TritonX-405 with CDs. Formation of host−guest complex mostly resulted in enhancement of water solubility of SWNTs.
Co-reporter:Tomoki Ogoshi, Takeshi Onodera, Tada-aki Yamagishi and Yoshiaki Nakamoto
Macromolecules 2008 Volume 41(Issue 22) pp:8533-8536
Publication Date(Web):October 30, 2008
DOI:10.1021/ma801921e
Polymerization of phenol with paraformaldehyde and catalytic sulfuric acid was carried out in room temperature ionic liquids based on imidazolium salts. The properties of ionic liquids were systematically varied by employing six different anions such as chloride, bromide, iodide, tetrafluoroborate, trifluoromethanesulfonate and hexafluorophosphate. In case of hydrophilic ionic liquids having chloride or bromide anion, phenol polymers with low molecular weight and narrow polydispersity were obtained. In contrast, using hydrophobic ionic liquids such as tetrafluoroborate and trifluoromethanesulfonate anions, high molecular weight phenol polymers were prepared. It is because interaction of the hydrophilic ionic liquids with phenol is stronger than that of the hydrophobic ionic liquids. The interaction between phenol and ionic liquids was investigated by 1H NMR measurements. Moreover, by using Brønsted acid ionic liquid carrying sulfuric acid moiety as a solvent, catalytic acid-free green polymerization of phenol with paraformaldehyde was accomplished. The ionic liquid was efficiently recovered and reused in new polymerization process of phenol.
Co-reporter:Tomoki Ogoshi, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2007 (Issue 45) pp:4776-4778
Publication Date(Web):13 Sep 2007
DOI:10.1039/B711800G
We report on hybrids of water-soluble calix[8]arenes and single-walled carbon nanotubes (SWCNTs); the hybrids formed supramolecular SWCNTs network polymer by adding guest dimer.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Kae Masaki and Tada-aki Yamagishi
Chemical Communications 2013 - vol. 49(Issue 38) pp:NaN3954-3954
Publication Date(Web):2013/03/26
DOI:10.1039/C3CC41592A
We report the first synthesis of bridged pillararenes. Meso-form pillar[6]arenes were diastereo-selectively formed by bridging units of a per-hydroxylated pillar[6]arene in an alternating up-and-down manner with dialkyldichlorosilanes.
Co-reporter:Tomoki Ogoshi, Yuto Ichihara, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2010 - vol. 46(Issue 33) pp:NaN6089-6089
Publication Date(Web):2010/07/23
DOI:10.1039/C0CC01644F
The preparation of a hybrid of graphene oxide and per-6-amino-β-cyclodextrin is reported. The hybrid formed a supramolecular graphene oxide polymer network upon addition of guest dimer.
Co-reporter:Tomoki Ogoshi, Ryohei Shiga, Masayoshi Hashizume and Tada-aki Yamagishi
Chemical Communications 2011 - vol. 47(Issue 24) pp:NaN6929-6929
Publication Date(Web):2011/05/23
DOI:10.1039/C1CC11864A
Introduction of bulky substituents such as benzyl and pyrenyl groups using click reactions inhibited or slowed the rotation of the units on the NMR chemical shift timescale. The perpyrenylated pillar[5]arene showed a thermally-responsive excimer emission, but a unit model of the perpyrenylated pillar[5]arene did not exhibit such a response.
Co-reporter:Tomoki Ogoshi, Keisuke Kitajima, Shuhei Fujinami and Tada-aki Yamagishi
Chemical Communications 2011 - vol. 47(Issue 36) pp:NaN10108-10108
Publication Date(Web):2011/08/03
DOI:10.1039/C1CC13546E
The reaction of 1,4-dimethoxybenzene and paraformaldehyde using AlBr3 yields multiple-deprotected pillar[5]arenes. A1/B2 di-deprotected pillar[5]arene can be isolated by silica gel chromatography and washing procedures. The X-ray structure and polymerization of the A1/B2 di-deprotected pillar[5]arene are reported.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Tomohiro Akutsu, Masanobu Naito and Tada-aki Yamagishi
Chemical Communications 2013 - vol. 49(Issue 78) pp:NaN8784-8784
Publication Date(Web):2013/07/31
DOI:10.1039/C3CC44672G
A planar-chiral pillar[5]arene derivative containing one π-conjugated unit was prepared. Chiroptical changes were observed upon addition of the achiral guest 1,4-dicyanobutane.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Keisuke Kitajima and Tada-aki Yamagishi
Chemical Communications 2011 - vol. 47(Issue 37) pp:NaN10292-10292
Publication Date(Web):2011/08/22
DOI:10.1039/C1CC14395F
A pillar[5]arene dimer was synthesized by linking a mono-hydroxylated pillar[5]arene with 1,4-bis(bromomethyl)benzene. The pillar[5]arene dimer formed stronger complexes with n-alkanes than did a monomeric pillar[5]arene.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chemical Communications 2012 - vol. 48(Issue 54) pp:NaN6844-6844
Publication Date(Web):2012/05/16
DOI:10.1039/C2CC32865H
A [2]rotaxane constructed from a per-ethylated pillar[6]arene as a wheel and a pyridinium derivative as an axle was prepared. The wheel segment of the per-ethylated pillar[6]arene moved from one station to another along the axle as a result of thermal stimuli.
Co-reporter:Tomoki Ogoshi, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2007(Issue 45) pp:NaN4778-4778
Publication Date(Web):2007/09/13
DOI:10.1039/B711800G
We report on hybrids of water-soluble calix[8]arenes and single-walled carbon nanotubes (SWCNTs); the hybrids formed supramolecular SWCNTs network polymer by adding guest dimer.
Co-reporter:Tomoki Ogoshi;Ayumi Inagaki;Tada-aki Yamagishi;Yoshiaki Nakamoto
Chemical Communications 2008(Issue 19) pp:
Publication Date(Web):2008/05/08
DOI:10.1039/B801546E
Single-walled carbon nanotubes (SWCNTs) were suspended in aqueous media with cucurbit[7]uril (CB7), while SWCNTs were insoluble with cucurbit[5]uril (CB5). Moreover, defection-selective solubilization of SWCNTs with CB7 was demonstrated.
Co-reporter:Tomoki Ogoshi, Kazuki Demachi, Keisuke Kitajima and Tada-aki Yamagishi
Chemical Communications 2011 - vol. 47(Issue 25) pp:NaN7166-7166
Publication Date(Web):2011/05/24
DOI:10.1039/C1CC12333E
The first synthesis of a monohydroxy pillar[5]arene has been carried out, by controlling the de-O-methylation of per-methylated pillar[5]arene. Using monohydroxy pillar[5]arene as an intermediate, mono-guest-functionalized pillar[5]arene was prepared. It formed a self-inclusion complex in CDCl3 whereas in acetone-d6 dethreading of the guest moiety took place.
Co-reporter:Tomoki Ogoshi, Daiki Yamafuji, Tada-aki Yamagishi and Albert M. Brouwer
Chemical Communications 2013 - vol. 49(Issue 48) pp:NaN5470-5470
Publication Date(Web):2013/04/24
DOI:10.1039/C3CC42612B
A [2]rotaxane has been constructed from a di-pyrene appended pillar[5]arene wheel, a pyridinium axle, and a perylene stopper. It shows efficient Förster resonance energy transfer from pyrene to perylene by formation of a mechanically interlocked [2]rotaxane.
Co-reporter:Tomoki Ogoshi, Masayoshi Hashizume, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2010 - vol. 46(Issue 21) pp:NaN3710-3710
Publication Date(Web):2010/04/13
DOI:10.1039/C0CC00348D
Water-soluble pillar[5]arene was synthesized by the introduction of carboxylate anions at both upper and lower rims. When cationic viologen salt was mixed with the water-soluble pillar[5]arene in aqueous media, a very stable 1 ∶ 1 host–guest complex was formed.
Co-reporter:Tomoki Ogoshi, Hitoshi Kayama, Daiki Yamafuji, Takamichi Aoki and Tada-aki Yamagishi
Chemical Science (2010-Present) 2012 - vol. 3(Issue 11) pp:NaN3226-3226
Publication Date(Web):2012/07/31
DOI:10.1039/C2SC20982A
A highly selective multiple host–guest complexation system based on pillar[5]arene and pillar[6]arene is reported. A pyridinium cation moiety is included in the pillar[5]arene cavity, but hardly forms a stable host–guest complex with pillar[6]arene. A 1,4-diazabicyclo[2.2.2]octane cation moiety forms a host–guest complex with pillar[6]arene, but not with pillar[5]arene. A synthetic route to mono-reactive pillar[6]arene is also developed, enabling the synthesis of pillar[6]arene with a pyridinium cation group at a single position. Based on the highly selective multiple host–guest complexation system and mono-reactive pillar[6]arene, a supramolecular polymer with alternating pillar[5]arene and pillar[6]arene units is constructed.
Co-reporter:Tomoki Ogoshi, Kumiko Yoshikoshi, Takamichi Aoki and Tada-aki Yamagishi
Chemical Communications 2013 - vol. 49(Issue 78) pp:NaN8787-8787
Publication Date(Web):2013/08/05
DOI:10.1039/C3CC44384A
We report a photo-reversible switching system between assembly and disassembly of a supramolecular polymer consisting of an azobenzene-bridged pillar[5]arene dimer.
Co-reporter:Tomoki Ogoshi, Naosuke Ueshima, Tada-aki Yamagishi, Yoshiyuki Toyota and Noriyoshi Matsumi
Chemical Communications 2012 - vol. 48(Issue 29) pp:NaN3538-3538
Publication Date(Web):2012/02/15
DOI:10.1039/C2CC30589E
A room-temperature ionic liquid containing macrocyclic compound pillar[5]arene in its core was synthesized. The ionic liquid showed high thermal stability, moderate ionic conductivity and solvent-free complexation ability with the guest tetracyanoethylene.
Co-reporter:Tomoki Ogoshi, Kenji Umeda, Tada-aki Yamagishi and Yoshiaki Nakamoto
Chemical Communications 2009(Issue 32) pp:NaN4876-4876
Publication Date(Web):2009/07/14
DOI:10.1039/B907894K
Pillar[5]arene from modified phenylethynyl groups was prepared; since the repeating π-conjugated units were largely π-delocalized via the through-space within the cavity, it showed temperature- and solvent-responsive blue-green emission.
Co-reporter:Tomoki Ogoshi ; Kazuyuki Masuda ; Tada-aki Yamagishi ;Yoshiaki Nakamoto
Macromolecules () pp:
Publication Date(Web):October 8, 2009
DOI:10.1021/ma901474b
![Heptacyclo[26.2.2.23,6.28,11.213,16.218,21.223,26]dotetraconta-3,5,8,10,13,15,18,20,23,25,28,30,31,33,35,37,39,41-octadecaene, 4,9,14,19,24,29,31,33,35,37,39,41-dodecaethoxy-](http://img.cochemist.com/data/images/1207685-12-8.png)
![Heptacyclo[26.2.2.23,6.28,11.213,16.218,21.223,26]dotetraconta-3,5,8,10,13,15,18,20,23,25,28,30,31,33,35,37,39,41-octadecaene, 4,9,14,19,24,29,31,33,35,37,39,41-dodecaethoxy-](http://img.cochemist.com/data/images/1207685-12-8_b.png)
![Aceticacid, 2,2'-[1,4-phenylenebis(oxy)]bis-, diammonium salt (9CI)](http://img.cochemist.com/ccimg/7000/6935-92-8.png)
![Aceticacid, 2,2'-[1,4-phenylenebis(oxy)]bis-, diammonium salt (9CI)](http://img.cochemist.com/ccimg/7000/6935-92-8_b.png)
