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DOI： 10.1002/anie.202204609

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/CHEM.202104212

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Authorship：Lead author   Language：English  

DOI： doi.org/10.1002/anie.202204609

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： doi.org/10.1002/chem.202104212

Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.202101226

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

A series of axially chiral 1,1′-binaphthyls with trialkylsiloxy (OSiR3) groups were synthesized. Among them, 1 a–c possessing OSiR3 groups at the 7,7′-positions and methyl groups at the 2,2′-positions were liquids at room temperature, and the neat liquids showed circularly polarized luminescence (CPL) (R=Bu; Φfl,liquid=0.21, |glum,liquid|=1.6×10−3). The |glum,liquid| value is the highest of pure liquids. These compounds remained liquid over a broad range of temperatures, down to −50 °C. Time-dependent DFT calculations indicated that in the excited state, the binaphthyls adopt a transoid conformation with a small angle between the electric and magnetic transition dipole moments (θμ,m=77°), which is a key factor in their CPL activity. The best binaphthyl dihedral angle in the excited state is approximately 110°.

DOI： 10.1002/anie.202101226

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

The one-stepC-methylenation of anilines and indoles with CO2and phenylsilane was catalyzed by a pentanuclear ZnIIcomplex to give diarylmethanesviageminal C-H and C-C bond formation. It is proposed that the zinc-hydride complex generatedin situis a catalytically active species and that bis(silyl)acetal is a key intermediate. When aniline was used as a substrate, both theC-methylenation andN-methylation proceeded.

DOI： 10.1039/D1CC03675K

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

A series of axially chiral binaphthyls and quaternaphthyls possessing two kinds of aromatic fluorophores, such as pyrenyl, perylenyl, and 4-(dimethylamino)phenyl groups, arranged alternately were synthesized by a divergent method. In the excited state, the fluorophores selectively formed a unidirectionally twisted exciplex (excited heterodimer) by a cumulative steric effect and exhibited circularly polarized luminescence (CPL). They are the first examples of a monomolecular exciplex CPL dye. This versatile method for producing exciplex CPL dyes also improved fluorescence intensity, and the CPL properties were not very sensitive to the solvent or to the temperature owing to the conformationally rigid exciplex. This systematic study allowed us to confirm that the excimer chirality rule can be applied to the exciplex dyes: left- and right-handed exciplexes with a twist angle of less than 90° exhibit (-)- and (+)-CPL, respectively. This journal is

DOI： 10.1039/D1SC04403F

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

A variety of carbazolyl-appended Schiff bases were readily synthesized from 1-formylcarbazoles and aniline derivatives. Boron complexation of the resulting ligands allowed for facile preparation of new carbazole-based BODIPY analogues showing solid-state fluorescence. Furthermore, some dyes were converted into chiral compounds through the Et2 AlCl-mediated incorporation of a binaphthyl unit. The chiral dyes showed aggregation-induced fluorescence and circularly polarized luminescence (CPL) with the ΦF and glum of up to 0.22 and -3.5×10-3 , respectively, in the solid state. The solid-state fluorescence and CPL were well characterized by the crystal packing analyses and DFT calculations.

DOI： 10.1002/chem.202001463

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

Hexameric and tetrameric porphyrin nanorings, Z6·T6 and Z4·T4, were synthesized in 53% and 14% yields, respectively, by the Sonogashira-type self-oligomerization of porphyrin monomer 1 using hexadentate template T6 and tetrapyridylporphyrin template T4. Template-free nanorings Z6 and Z4 were also prepared. The femtosecond transient absorption measurements revealed fast excitation energy hopping (EEH) along these nanorings with hopping rates of 2-5 ps. Treatment of Z6 with chiral template CT6 gave Z6·CT6 showing circular dichroism (CD) and circularly polarized luminescence (CPL) in the absorption and fluorescence regions of Z6, respectively, which indicates chirality transfer from CT6 to Z6.

DOI： 10.1021/jacs.0c07707

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

A series of carbazole-based boron dipyrromethenes (BODIPYs) 2 a-g bearing binaphthyl units have been synthesized by the Et2 AlCl-mediated reaction of the corresponding BODIPY difluorides 1 a-g with 1,1'-binaphthalene-2,2'-diol. Substituents such as halogen, nitrile, and amino groups were tolerated under the reaction conditions, and the reaction of the phenylethynyl-substituted 1 h gave (R,R)-3 h bearing two binaphthyl units. The chiroptical properties of these dyes with different substituents were investigated by UV/Vis, CD, fluorescence, and circularly polarized luminescence (CPL) spectroscopy. The CD spectra showed Cotton effects in the absorption region of the BODIPY moieties. In addition, they showed CPL both in solution and in the solid state. Interestingly, several dyes recorded higher glum values in the solid state, probably due to intermolecular interactions. Because (R,R)-3 h recorded relatively low glum values, the diastereomer (R,S)-3 h was prepared. The (R,S) diastereomer showed intense CPL, which suggests a synergetic effect of the two binaphthyl groups. Finally, chiral carbazole-based BODIPY dimers have been synthesized for the first time and their chiroptical properties were investigated. They showed redshifted fluorescence and CPL, which reached the near-IR (NIR) region in the solid state.

DOI： 10.1002/chem.201904954

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Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

A series of pyrenes sandwiched by axially chiral 1,1′-binaphthyls were synthesized. Among them, (R,R)-3 possessing 2-hydroxy-3,3′-dimethylbinaphthyls exhibited solvent-dependent inversion of the sign of circularly polarized luminescence (CPL) without a change in emission wavelength. The (-)- and (+)-CPL were detected in nonpolar and polar solvents, respectively, with glum values of -0.012 and +0.012. This switching property originates from the inversion of excimer chirality caused by the presence or absence of intermolecular hydrogen bonds in the excited state. The CPL intensity was also changed by variation of the temperature and concentration.

DOI： 10.1021/jacs.9b13184

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Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

Metal clusters in nature and artificial systems are known to exhibit excellent catalytic activities. Among various coordination systems, macrocyclic multinuclear metal complexes have unique structural features and great potential in organic synthesis. The multiple metal centers in a macrocyclic framework act as specific sites for the binding and activation of substrates, showing high catalytic activity and selectivity as a result of the cooperative effect of the multiple metal centers and robustness originating from macrocyclic skeletons. Most of them are precisely designed and synthesized, while occasionally, nice complexes also emerge from a fortuitous combination of metal ions and ligands. Here we overview the recent achievements of (i) multinuclear metal complexes with a covalently-linked macrocyclic ligand (category A), (ii) multinuclear metal complexes forming a macrocyclic skeleton (category B), and (iii) self-assembled supramolecular coordination complexes (category C). Various organic reactions catalyzed by these coordination systems are summarized here.

DOI： 10.1039/C9CY01894H

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

A series of axially chiral peri-xanthenoxanthenes (PXXs) were synthesized from 1,1′-bi-2-naphthol without optical resolution. These are the first examples of chiral PXXs. Among them, PXX 5 with two naphthalene rings connected via a methylenedioxy bridge and a chiral axis displayed intense fluorescence (FL) and circularly polarized luminescence (CPL) both in solution (φFL of 0.72 and |glum| of 1.4 × 10-3) and in the solid state (φFL of 0.13 and |glum| of 4.8 × 10-3). The bridged structure of PXX 5 adjusts the angle between the vectors of the electric and magnetic transition dipole moments, which is essential for showing intense CPL activity.

DOI： 10.1021/jacs.9b06240

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

DOI： 10.1021/acsphotonics.9b00185

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Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Unique self-assembled macrocyclic multinuclear ZnII and NiII complexes with binaphthyl-bipyridyl ligands (L) were synthesized. X-ray analysis revealed that these complexes consisted of an outer ring (Zn3L3 or Ni3L3) and an inner core (Zn2 or Ni). In the ZnII complex, the inner Zn2 part rotated rapidly inside the outer ring in solution on an NMR timescale. These complexes exhibited dual catalytic activities for CO2 fixations: synthesis of cyclic carbonates from epoxides and CO2 and temperature-switched N-formylation/N-methylation of amines with CO2 and hydrosilane.

DOI： 10.1002/anie.201904224

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

A versatile method for converting various fluorescent polycyclic aromatic hydrocarbons into circularly polarized luminescence (CPL) excimer dyes with high glum and φFL values is reported. This method involves the functionalization of a chiral quaternaphthyl with six fluorophores via ester linkages in the last step of the synthesis. The usefulness of this approach was demonstrated for 1-, 2-, and 4-pyrenyl, 2- and 3-perylenyl, and 2-anthryl dyes. Most of them are the first or rare examples of CPL dyes. In the ground state, the fluorophores are tightly arranged by cumulative steric and electronic effects. In the excited state, the fluorophores form a twist excimer that maintains the ground-state conformations. The local chiral excimer directly affected the CPL properties. The systematic study on the signs of the CPLs allowed us to find a rule called the excimer chirality rule: right- and left-handed excimers exhibit (+)- and (-)-CPL, respectively.

DOI： 10.1021/jacs.9b02582

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

Hemisquaramide tweezers, a new family of H-bond donor organocatalysts, are reported. The catalysts could be synthesized within two steps. Among them, H 8 -binaphthyl-linked hemisquaramide 7 markedly accelerated the synthesis of cyclic carbonates from epoxides and CO 2 . The reactions proceeded well under mild and solvent-free conditions. Kinetic resolution was also achieved at -20 °C (s = 3.0). The adjustable bite angle and orientation of the two NH groups of the catalysts are important for the high activity.

DOI： 10.1021/acs.orglett.9b00117

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

Doubly (R)-binaphthyl-strapped porphyrins with methylene chains were synthesized. The CD spectra showed the positive Cotton effect around the Soret bands, and several porphyrins showed CPL. In addition, we found that the chiral porphyrins were applicable to kinetic resolution of epoxide with CO2.

DOI： 10.1039/C8CC09114E

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

Chiral carbazole-based BODIPYs with a binaphthyl unit were synthesized via an Al-mediated reaction. Et2AlCl was found to be a convenient reagent for the reaction to give the chiral BODIPYs in high yields. It has been shown for the first time that these chiral carbazole-based BODIPYs show circularly polarized luminescence (CPL) both in solution and in the solid state.

DOI： 10.1039/C9CC00894B

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Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

Copyright © 2018 American Chemical Society. Chiral macrocyclic receptors 1 with multiple hydrogen-bonding sites in the cavity were synthesized and used as NMR chiral solvating agents (CSAs). The Suzuki-Miyaura cross-coupling reaction gave rapid access to a series of variants 1b-p of unsubstituted parent compound 1a. Among them, 1d with the 4-cyanophenyl group at the 3,3′-positions of the binaphthyl moiety was the most excellent CSA for a benchmark analyte compound, 2-chloropropionic acid (CPA); both of the quartet and doublet signals of CPA were split most completely in CDCl3. Binding constants (Ka) determined in CDCl3by NMR titrations indicated that (R)-1d was the most enantioselective (Ka(S)/Ka(R) = 5.4). Interestingly, the Kavalue of (R)-1d for (S)-CPA (5900) was greater than that of (R)-1a for (S)-CPA (3080), which strongly suggests an attractive interaction between the 4-cyanophenyl group of (R)-1d and (S)-CPA. The X-ray crystal structure of 1d indicates that one of the two H atoms meta to the cyano group is directed toward the cavity. DFT calculations suggested that this H atom of the 4-cyanophenyl group of (R)-1d forms a weak hydrogen bond with the Cl atom of (S)-CPA (C-H···Cl-C hydrogen bond).

DOI： 10.1021/acs.joc.8b01327

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Other Link： http://orcid.org/0000-0003-4979-7375

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley-VCH Verlag  

In this study, room-temperature mechanical rubbing is used to control the 3D orientation of small π-conjugated molecular systems in solution-processed polycrystalline thin films without using any alignment substrate. High absorption dichroic ratio and significant anisotropy in charge carrier mobilities (up to 130) measured in transistor configuration are obtained in rubbed organic films based on the ambipolar quinoidal quaterthiophene (QQT(CN)4). Moreover, a solvent vapor annealing treatment of the rubbed film is found to improve the optical and charge transport anisotropy due to an increased crystallinity. X-ray diffraction and atomic force microscopy measurements demonstrate that rubbing does not only lead to an excellent 1D orientation of the QQT(CN)4 molecules over large areas but also modifies the orientation of the crystals, moving molecules from an edge-on to a face-on configuration. The reasons why a mechanical alignment technique can be used at room temperature for such a polycrystalline film are rationalized, by the plastic characteristics of the QQT(CN)4 layer and the role of the flexible alkyl side chains in the molecular packing. This nearly complete conversion from edge-on to face-on orientation by mechanical treatment in polycrystalline small-molecule-based thin films opens perspectives in terms of fundamental research and practical applications in organic optoelectronics.

DOI： 10.1002/adfm.201707038

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society ({ACS})  

A series of chiral cyclic dyads, axially chiral binaphthyls linked to a 3,3′-bipyridyl, was synthesized. The dyad 2 bearing methoxy groups exhibited ON/OFF properties in circularly polarized luminescence (CPL), yielding a |glum| of 1.6 × 10-3 or 0 without any change in fluorescence. This type of CPL switch is unprecedented. Regioisomer 4 exhibited a dextro/levo rotation switching ability in [α]D. X-ray structures as well as experimental and theoretical analyses suggested that the switching properties depended on conformational changes.

DOI： 10.1021/jacs.8b01860

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Other Link： http://orcid.org/0000-0003-4979-7375

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

(R,R,R)-Quaternaphthyls possessing eight and six pyrenes (compounds 4 and 3) displayed intense excimer-CPL. The glum values in solution and in the solid state were +0.034-0.037 and +0.0053-0.0056, respectively. The glum values of 3 and 4 were indistinguishable, indicating that the pyrenes of 3 and 4 assumed the same conformation, even in excited states. The intense CPL was caused by conformationally rigid pyrenes arranged via the cumulative steric effects along the quaternaphthyl axis.

DOI： 10.1039/C7CC09187G

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Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry ({RSC})  

© 2018 The Royal Society of Chemistry. Calix[4]pyrrole 1, calix[4]arene 2, or porphyrin 3 together with tetrabutylammonium iodide (TBAI) catalyzed the conversion of epoxides and CO2into cyclic carbonates. Among them, meso-octamethylcalix[4]pyrrole 1a, which was synthesized easily in one step by the acid-catalyzed condensation of pyrrole with acetone, was found to be a very active and robust organocatalyst. DFT calculations suggested that 1a adopts a 1,3-alternate conformation to stabilize the anionic species generated during the catalysis. In the key transition state of the epoxide ring-opening step, one pyrrolic NH group and the tetrabutylammonium (TBA) cation activate the epoxide by hydrogen bonding while another NH group on the opposite side guides the I-anion, which is located away from the TBA cation, to the backside attack on the epoxide.

DOI： 10.1039/C8CY00941D

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We developed several naphthalene oligomers with contiguous chiral axes as chiroptical dyes. RS-alternating oligomers with the 2, 2′-methylenedioxy bridges take a V-shaped conformation with a notably extensive conjugation in the rod direction, leading to high fluorescence in solution and in the solid state (ΦFL, solution = 0.64 and ΦFLsolid = 0.13 for an octamer). Theoretical studies indicated that the dihedral angles of naphthalene rings were held steady 48-49°, and both the HOMO and LUMO were spread throughout the molecule. It should be noted that the bridged R,R,R,R,R,R,R)-naphthalene octamer showed more intense fluorescence (FL) and circularly polarized luminescence (CPL) (ΦFL, solution = 0.90, g lum, solution = + 2.2 × 10-3, ΦFL, solid = 0.22, and g lum, solid = + 7.0 × 10-3). The high ΦFL and glum values were due to the rigidity. Moreover, the octamer molecules were incapable of forming efficiently stacked structures due to the non-planar conformation, which led to a high ΦFLsolid value in the solid state. A(R,R, R)-naphthalene tetramer possessing eight pyrenes displayed intense excimer-FL and CPL (ΦFLsolution = 0.25, glum, solution = + 0.034, ΦFL, solid = 0.28, and g lum, solid = +5.3 × 10-3). Pyrenes densely connected to a naphthalene tetramer via ester linkers were conformationally rigid with right-handed chirality and were important for obtaining strong CPL.

DOI： 10.5059/yukigoseikyokaishi.76.885

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley-Blackwell  

Annulation reactions of the butadiyne-bridged carbazole dimer 1 produced carbazole-based chalcogenaisophlorins 2-4, which were transformed into the corresponding palladium complexes 2Pd-4Pd. The structures were characterized by NMR spectroscopy and X-ray diffraction analysis. Metallation fixed the structures which displayed weak antiaromatic character derived from the 20 isophlorin framework. These complexes showed weak near-infrared (NIR) absorption typical for antiaromatic porphyrinoids in solution. In addition, 2Pd and 3Pd showed relatively strong solid-state NIR absorption. X-ray diffraction analyses of 2Pd and 3Pd revealed trimeric and dimeric stacked layered structures, respectively, and DFT calculations suggest that the solid-state NIR absorption is ascribed to intermolecular charge transfer.

DOI： 10.1002/cplu.201700470

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPANDIDOS PUBL LTD  

Reactive oxygen species (ROS) are generated in the cell through multiple mechanisms. Intracellular ROS are rapidly detoxified by various enzymatic and non-enzymatic mechanisms; however, disruption of the oxidant-antioxidant balance causes oxidative stress and elicits cell damage. The oxidative stress induced by chemotherapy is known to cause side effects in patients with cancer. However, few studies have examined whether anticancer drugs induce oxidative stress in cancer cells. Furthermore, the precise mechanism by which anticancer drugs induce the generation of ROS remains unclear. In the present study, to investigate whether anticancer drugs induce oxidative stress, DLD-1 human colorectal cancer cells were treated with 20 different anticancer drugs and then stained with CellROX (R) ROS detection reagent. Furthermore, an oxygen radical absorbance capacity assay in the presence of copper was performed to estimate the oxidative activities of the anticancer drugs in the absence of cells. The data of the present study using assay methods in the presence and absence of cells suggest that nimustine, actinomycin D, doxorubicin, mitomycin C, mitoxantrone, carmofur, gemcitabine, mercaptopurine, camptothecin, paclitaxel, vinblastine, and vinorelbine are able to induce oxidative stress.

DOI： 10.3892/ol.2017.6931

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The temperature and concentration dependencies of the crystallization of two small-molecular semiconductors were clarified by constructing quasi-phase diagrams at air/oil interfaces and in bulk oil phases. A quinoidal quaterthiophene derivative with four alkyl chains (QQT(CN)-4) in 1,1,2,2-tetrachroloethane (TCE) and a thienoacene derivative with two alkyl chains (C8-BTBT) in o-dichlorobenzene were used. The apparent crystal nucleation temperature (T-n) and dissolution temperature (T-d) of the molecules were determined based on optical microscopy examination in closed glass capillaries and open dishes during slow cooling and heating processes, respectively. Tn and Td were considered estimates of the critical temperatures for nuclear formation and crystal growth, respectively. The Tn values of QQT(CN)-4 and C8-BTBT at the air/oil interfaces were higher than those in the bulk oil phases, whereas the Td values at the air/oil interfaces were almost the same as those in the bulk oil phases. These Gibbs adsorption phenomena were attributed to the solvophobic effect of the alkyl chain moieties. The temperature range between Tn and Td corresponds to suitable supercooling conditions for ideal crystal growth based on the suppression of nucleation. The Tn values at the water/oil and oil/glass interfaces did not shift compared with those of the bulk phases, indicating that adsorption did not occur at the hydrophilic interfaces. Promotion and inhibition of nuclear formation for crystal growth of the semiconductors were achieved at the air/oil and hydrophilic interfaces, respectively.

DOI： 10.1021/acs.langmuir.7b01603

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Among chiral macrocycles 1 synthesized, lm with the 3,5-bis(trifluoromethypphenylethynyl group was the best organocatalyst for the enantioselective synthesis of cyclic carbonates from disubstituted or monosubstituted epoxides and CO2. The X-ray crystal structure of lm revealed a well-defined chiral cavity with multiple hydrogen-bonding sites that is suitable for the enantioselective activation of epoxides. A catalytic cycle proposed was supported by DFT calculations.

DOI： 10.1021/acs.orglett.7b01838

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

To synthesize ladder-type polyamides by construction of two amide bonds successively, 2,5-diaminoterephthalic acid derivatives bearing anthranilic acid ester and isatoic anhydride moieties were synthesized and their polymerization was investigated. Polymerization of the methyl ester monomer proceeded in the presence of lithium hexamethyldisilazide (LiHMDS) as a base in tetrahydrofuran (THF). However, mass spectroscopic analysis of the product suggested that not only the bis(trimethylsilyl)amide anion of LiHMDS but also the methoxide anion eliminated at the second amide-linkage formation reaction decomposed the isatoic anhydride unit of the growing oligomer by nucleophilic attack to disturb the polymerization. To reduce the nucleophilicity of the eliminated anion, methyl ester of the monomer was changed to phenyl ester and its polymerization was studied. The reaction conditions were optimized, and the best result was obtained when the polymerization was conducted in the presence of 1.0 equivalent of LiHMDS without additives in THF at 50 degrees C. (C) 2017 Wiley Periodicals, Inc.

DOI： 10.1002/pola.28625

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A series of oligonaphthodioxepins was synthesized, revealing a helically arranged octamer, (R,R,R,R,R,R,R)-3, which showed intense circularly polarized luminescence (CPL) both in solution and in the solid state. The fluorescence quantum yields (Phi(FL)) in solution and in the solid state were 0.90 and 0.22, respectively, and the glum values in solution and in the solid state were vertical bar 2.2 x 10 (-3) 3 and + 7.0 x 10 (-3) , respectively. This is one of the highest solid-state CPL glum values yet reported. The high FFL and glum values were due to the rigidity, as well as to the fact that (R, R, R, R, R, R, R)-3 was a non-planar molecule. Moreover, (R, R, R, R, R, R, R)-3 was highly stable both chemically and stereochemically.

DOI： 10.1002/chem.201702143

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We report on the use of microcrystallization in capillaries to fabricate patterned crystalline microstructures of the low-bandgap ambipolar quinoidal quaterthiophene derivative (QQT(CN)(4)) from a chloroform solution. Aligned needle -shaped QQT(CN)(4) crystals were formed in thin film microstructures using either open-or closed capillaries made of polydimethylsiloxane (PDMS). Their charge transport properties were evaluated in a bottom-gate top-contact 10(-5) transistor configuration. Hole and electron mobilities were found to be as high as 0.17 and 0.083 cm(2) V-1 s(-1), respectively, approaching the values previously obtained in individual QQT(CN)(4) single crystal microneedles. It was possible to control the size of the needle crystals and the microline arrays by adjusting the structure of the PDMS mold and the concentration of QQT(CN)(4) solution. These results demonstrate that the microcrystallization in capillaries technique can be used to simultaneously pattern organic needle single crystals and control the microcrystallization processes. Such a simple and versatile method should be promising for the future development of high-performance organic electronic devices.

DOI： 10.1021/acsami.5b12713

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

An axially chiral binaphthyl-bipyridyl cyclic dyad in which the two units are connected by short -CH2O- linkers Was synthesized. Experimental and theoretical analyses indicate that the (R)-binaphthyl unit in the dyad induces (R)-chirality in the bipyridyl unit, both in the solid state and in solution. It is shown that vibrational circular dichroism (VCD) is useful to determine the twisting pattern of 2,2'-bipyridyl compounds. The dyad shows crystallization-induced emission enhancement (CIEE).

DOI： 10.1021/acs.orglett.5b02041

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A simple and versatile solution-processing method based on molecular self-assembly is used to fabricate organic single crystal microwires of a low bandgap quinoidal oligothiophene derivative. Individual single crystal microwire transistors present well-balanced ambipolar behaviour with hole and electron mobilities as high as 0.4 and 0.5 cm(2) V-1 s(-1), respectively.

DOI： 10.1039/c4cc09608h

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Polymer ferroelectric-gate field effect transistors (Fe-FETs) employing ferroelectric polymer thin films as gate insulators are highly attractive as a next-generation non-volatile memory. For minimizing gate leakage current of a device which arises from electrically defective ferroelectric polymer layer in particular at low operation voltage, the materials design of interlayers between the ferroelectric insulator and gate electrode is essential. Here, we introduce a new solution-processed interlayer of conductive reduced graphene oxides (rGOs) modified with a conjugated block copolymer, poly(styrene-block-paraphenylene) (PS-b-PPP). A FeFET with a solution-processed p-type oligomeric semiconducting channel and ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) insulator exhibited characteristic source-drain current hysteresis arising from ferroelectric polarization switching of a PVDF-TrFE insulator. Our PS-b-PPP modified rGOs (PMrGOs) with conductive moieties embedded in insulating polymer matrix not only significantly reduced the gate leakage current but also efficiently lowered operation voltage of the device. In consequence, the device showed large memory gate voltage window and high ON/OFF source-drain current ratio with excellent data retention and read/write cycle endurance. Furthermore, our PMrGOs interlayers were successfully employed to FeFETs fabricated on mechanically flexible substrates with promising non-volatile memory performance under repetitive bending deformation. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.orgel.2014.07.035

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Various metal-bridged single and double helical complexes of pi-conjugated ligand molecules, bidipyrrins, were prepared. The introduction of terminal end units enabled the formation of chiral single and double helices; their spectroscopic properties and temperature-dependent behaviors were examined.

DOI： 10.1246/cl.140260

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Using a bottom-up method, we prepared a series of oligonaphthofurans composed of alternating naphthalene rings and furan rings. The largest compound (compound 25) contained 8 naphthalene units and 7 furan units. DFT calculations revealed that these compounds were fan-shaped molecules and each naphthalene ring was oriented in an alternate mountain-valley fold conformation because of steric repulsion by the hydrogens at the pen-positions. We investigated the optical properties that derived from their fan-shaped and mountain-valley sequences. As the number of aromatic rings of the oligonaphthofurans increased, the peaks of the longest wavelength absorptions in the UV-vis spectra (HOMO-LUMO energy gap) of these compounds steadily red-shifted, although the shapes of spectra were not sustained because of the decreasing molar absorption coefficients (epsilon's) of their lambda(max). We compared our results with those reported for other types of oligoaromatic compounds such as acenes 1, ethene-bridged p-phenylenes 2, rylenes 3, oligofurans 4, and oligonaphthalenes 5. The slopes of the plots between the transition energies (HOMO-LUMO energy gap) of the oligoaromatic compounds and the reciprocal of the number of aromatic rings indicated that the efficiency of pi conjugation of the oligonaphthofurans was comparable with that of linear and rigid acenes and rylenes. The higher-order compounds 22 and 25 aggregated even under high dilution conditions (similar to 10(-6) M).

DOI： 10.1021/ja502209w

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

High-performance non-volatile memory that can operate under various mechanical deformations such as bending and folding is in great demand for the future smart wearable and foldable electronics. Here we demonstrate non-volatile solution-processed ferroelectric organic field-effect transistor memories operating in p- and n- type dual mode, with excellent mechanical flexibility. Our devices contain a ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) thin insulator layer and use a quinoidal oligothiophene derivative (QQT(CN)4) as organic semiconductor. Our dual-mode field-effect devices are highly reliable with data retention and endurance of > 6,000 s and 100 cycles, respectively, even after 1,000 bending cycles at both extreme bending radii as low as 500 mu m and with sharp folding involving inelastic deformation of the device. Nano-indentation and nano scratch studies are performed to characterize the mechanical properties of organic layers and understand the crucial role played by QQT(CN)4 on the mechanical flexibility of our devices.

DOI： 10.1038/ncomms4583

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The crystal structure of N-isopropylanthranilic acid trimer was characterized by a single-crystal X-ray diffraction method to study the conformation of oligo(o-benzamide). The compound crystallized in a triclinic space group, P1, with a = 7.720(4)Å, b = 9.006(4)Å, c = 20.131(9)Å, α = 92.459(7)°, β = 95.299(7)°, γ = 91.099(7)°, V = 1391.9(11)Å3, and Z = 2. In the crystal structure, one of the amide linkages adopts a cis conformation, while the other adopts a trans conformation. © 2014, The Japan Society for Analytical Chemistry.

DOI： 10.2116/xraystruct.30.35

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

As new and chiral macrocyclophanes with unique structures, variously sized Pn and Mn (n=2-7=number of 'rod' segments) with D-2-D-7 symmetry were constructed by alternating connection of axially chiral binaphthyls and linear biphenyls via -CH2O- moieties, so that the macrocycle consists of multiple rod-like naphthalene biphenyl naphthalene units linked together at the binaphthyl bonds. The dihedral angle of the two naphthalene rings of binaphthyl is restricted to around 90 degrees, and the calculated values of strain energy difference per naphthalene biphenyl unit in P2-P7 are almost independent of the macrocycle size, presumably owing to the flexibility of the -CH2O- connectors. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2013.11.081

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Dimers of appropriately arranged anion-responsive pi-conjugated moieties form helical structures by interaction with chiral anions. Terphenyl-bridged dimers of dipyrrolyldiketone boron complexes show chirality induced by binding L-amino acid anions, as observed by circular dichroism (CD) and circularly polarized luminescence (CPL). The preferred configurations of helical structures depend on the geometries of the terphenyl spacer moieties.

DOI： 10.1021/ol402895r

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Anion-responsive -conjugated compounds having chiral alkyl chains were synthesized. Circular dichroism (CD) and circularly polarized luminescence (CPL) were observed in the solution-state assemblies of the chiral anion receptors and those of their anion complexes as salts of a planar triazatriangulenium cation. The CD and CPL spectral patterns of the ion-pair-based assemblies were completely opposite to those of the anion-free assemblies, and this suggests that anion binding and subsequent ion pairing change the chirality of the assembly modes.

DOI： 10.1002/chem.201301737

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Oriented salts from planar charged species were prepared by combining positively and negatively charged receptor-anion complexes with similar geometries using dicationic and electronically neutral π-conjugated receptors. Phenylene-or pyrimidine-bridged bis(imidazolium) dicationic anion receptors formed monocationic receptor-Cl- complexes that were accompanied by a free Cl-. This free Cl- was subsequently captured by pyrrole-based neutral anion receptors to form negatively charged receptor-Cl- complexes. The ion pair of the resulting positively and negatively charged planar receptor-Cl- complexes could produce a supramolecular octane gel, adopting a lamellar self-organized structure in its xerogel state. On the other hand, the solid-state ion pairs had hexagonal columnar mesophases, which formed via alternate stacking of the positively and negatively charged planar receptor-Cl- complexes. By use of the flash-photolysis time-resolved microwave conductivity technique, the one-dimensional charge-carrier transporting property, with a mobility of 0.05 cm2 V-1 s-1, was determined for the newly prepared solid-state ion pairs. © 2013 American Chemical Society.

DOI： 10.1021/ja4071333

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Polygon-like [2+2]- and [3+3]-type metal complexes were prepared from dipyrrin dimers connected by acute-angled spacers. The electrical conduction depends strongly on the packing alignment of the compounds, revealing the presence of effective hopping pathways for holes with relatively high mobility up to 0.11cm(2)V(-1)s(-1) along the aligned axis of [3+3]-type metal-bridged assemblies. These observations correlated with the geometrical control of the -conjugated metal complexes in the cyclic structures, which enables their ordered arrangement in the assemblies.

DOI： 10.1002/chem.201302028

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Covalent linkages: Zwitterion-based covalent linkages were observed in cyclic oligomers and in dispersed polymers based on monomers. Addition of acids and bases promoted transitions between monomeric species and the oligomeric and/or polymeric states. Exchange of constituent monomer units in the cyclic oligomers was observed in the solution state, whereas the polymers obtained as precipitates from CH3CN were not converted to the cyclic oligomers (see scheme). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/chem.201300704

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Language：English   Publishing type：Research paper (scientific journal)  

This paper reports the formation and properties of covalently strapped double helices of bidipyrrin-ZnII complexes, where four dipyrrin chromophores interact with one another by strong exciton coupling. Thorough experimental examination, UV/vis, CD and 1H NMR spectra, and theoretical studies suggest the existence of two modes of the double helix depending on the dihedral angles between two of the dipyrrin units at the pyrrole α-α bond. In fact, the changes of the modes were observed according to the lengths of straps as well as the temperatures. © 2013 The Royal Society of Chemistry.

DOI： 10.1039/c2sc21913a

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPIE-INT SOC OPTICAL ENGINEERING  

Light-driven supramolecular chiral materials containing an azobenzene moiety as a photoresponsive part and binaphthyl moiety as a chiral part were designed. We found that the dynamic molecular twisting motion of the binaphthyl moiety could be achieved by irradiation of UV or visible light to cause photoisomerization of the azobenzene moiety. The twisting motion induced by the photochromic reaction gave rise to large change in the molecular structure and the value of optical rotation. The chiral materials were demonstrated to behave uniquely as photomodulation of liquid-crystalline helical structures and non-destructive erasable chiroptical memory through photoinduced switching of the dihedral angle of the binaphthyl moiety.

DOI： 10.1117/12.2021602

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

We report on singlet-singlet annihilation and exciton diffusion in as-prepared p-type and annealed n-type thin films of the low-bandgap quinoidal quaterthiophene [QQT(CN)4] using ultrafast transient absorption measurements. The decay dynamics of exciton populations are well described by a one-dimensional diffusion-limited bimolecular recombination, indicating that the singlet excitons migrate preferentially along the stacking direction. Our results show that the exciton diffusion constants in QQT(CN)4 films do not vary significantly upon thermal annealing. Exciton diffusion lengths are measured to be as high as 4 and 5 nm in as-prepared and annealed QQT(CN)4 films, respectively. We also observe an influence of the excitation densities on the singlet exciton diffusion, which is attributed to phonon scattering. Because of the possibility of patterning p-n regions in QQT(CN)4 films by thermal nanolithography techniques, this study provides important insight not only into the photophysical properties of quinoidal oligothiophene derivatives but also for their future integration into high-performance p-n nanostructured near infrared light-sensing devices.

DOI： 10.1039/c2cp43705h

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A method for synthesizing highly strained cyclic structures by combining photochromic and synthetic reactions is described. Tightly linked azobenzene binaphthyl dyads (R)-4 and (R)-6 could not be obtained by conventional cyclization, but continuous application of photoirradiation, which induced (E)->(Z) isomerization of the azobenzene moiety, allowed the cyclization reaction to proceed, affording the desired chiral azobenzenophanes.

DOI： 10.1021/ol300992d

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Axially chiral binaphthyl-azobenzene cyclic dyads in which the two moieties are connected by two linkers of different lengths were synthesized. In the case of benzylated-binaphthyl analogue 2b, photoirradiation resulted in a dramatic change of the CD spectrum and optical rotation. Experimental and theoretical analyses indicated that the dihedral angle of the two naphthalene rings is strongly coupled to the azobenzene photoisomerization; cis-azobenzene induces a transoid-binaphthyl structure, while trans-azobenzene Induces a cisold-binaphthyl structure.

DOI： 10.1021/ol203053q

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

We report on the charge transport and absorption properties of a low bandgap quinoidal oligothiophene derivative [QQT(CN)4]. Organic field-effect transistors based on QQT(CN)4 thin films show an ambipolar p-type dominant behavior and can be converted to n-type by thermal annealing at 100 degrees C for 30 minutes. Absorption spectra and atomic force microscopy measurements carried out in both neat films and polymer blends provide new important insights into the role of the degree of aggregation and the intermolecular interactions on the semiconducting and photophysical properties of this organic electronic material.

DOI： 10.1080/15421406.2012.701107

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Asymmetry through ion pairing: Upon addition of chloride and bromide ions, as chiral ammonium salts, to solutions of pyrrole-based π-conjugated linear oligomers, helical structures form with asymmetric induction, which is guided by the formation of diastereomeric ion pairs with chiral counter cations (see picture). These ions pairs exhibit circular dichroism (CD) and strong circularly polarized luminescence (CPL) with glumvalues of greater than 0.1. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/anie.201202196

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The absolute configuration of a binaphthylazobenzene dyad 2b, which has a chiral axis and a chiral plane, was determined by comparing the experimental circular dichroism (CD) spectra with the theoretical CD spectra calculated by the time-dependent (TD)-DFT method. The CD signals of the trans-azobenzene moiety indicated that the two benzene rings of this moiety are twisted unidirectionally. It is suggested that these dyads with shorter linkers may be suitable for use as chiroptical switches.

DOI： 10.1021/jo201578z

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

We report on the fabrication and characterization of ambipolar organic field-effect transistors based on the solution-processable quinoidal oligothiophene [QQT(CN)4] and using a new fluorinated polymer (AL-X601) with a dielectric constant of 3.1 as dielectric material layer. As-prepared devices show ambipolar transport with hole and electron field-effect mobilities of 6 x 10(-2) and 5 x 10(-3) cm(2)/V s respectively as well as an on and off state current ratio higher than 10(3). Influence of a thermal annealing on the device performances was investigated and was found to lead to a majority carrier type conversion from a p-type to an n-type dominant behavior. QQT(CN)4 based field-effect transistors and complementary inverters fabricated on flexible substrates and using Al-X601 as gate dielectric material show high performance and good mechanical stability. (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.optmat.2011.03.015

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Solution-processed ambipolar organic field-effect transistors based on dicyanomethylene-substituted quinoidal quaterthiophene derivative [QQT(CN) 4] are fabricated using various gate dielectric materials including cross-linked polyimide and poly-4-vinylphenol. Devices with spin-coated polymeric gate dielectric layers show a reduced hysteresis in their transfer characteristics. Among the insulating polymers examined in this study, a new fluorinated polymer with a low dielectric constant of 2.8 significantly improves both hole and electron field-effect mobilities of QQT(CN)4 thin films to values as high as 0.04 and 0.002 cm(2) V(-1) s(-1). These values are close to the best mobilities obtained in QQT(CN)4 devices fabricated on SiO(2) treated with octadecyltrichlorosilane. The influence of the metal used for source/drain metal electrodes on the device performance is also investigated. Whereas best device performances are achieved with gold electrodes, more balanced electron and hole field-effect mobilities could be obtained using chromium.

DOI： 10.1088/0022-3727/44/20/205102

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Language：English   Publisher：MDPI AG  

Optically active binaphthyl-azobenezene cyclic dyads were synthesized to develop a photochromic switching molecule. Azobenezene moieties were cis-trans isomerized by photoirradiation. As a reflection of the structural change, the specific optical rotation and circular dichroism underwent significant shifts. Under certain conditions, the positive-negative and zero-positive (or zero-negative) signals were reversed. Optical rotation may potentially be applied in noise-cancelling nondestructive photoswiches. The conformations were studied by experimental and theoretical methods. The results revealed that the helical chirality, (P) or (M), of the cis-azobenzene moiety was induced by intramolecular axial chirality. The twist direction depended on the axial chirality as well as the azobenzene linkage position to the binaphthyls, but was independent of the identity of substituted groups. 2,2'-Linked-(R)-binaphthyl was found to induce cis-(P)-azobenzene, whereas symmetrically 7,7'-linked-(R)-binaphthyl was found to induce cis-(M)-azobenzene.

DOI： 10.3390/molecules16021603

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The cis and trans forms of the azobenzene skeleton differ significantly in length and therefore are frequently used as photochromic parts for changing absorption and fluorescence properties, in addition to association constants when they are hosts.Although optically active compounds with azobenzene adducts have been reported,few studies have examined the asymmetry of the azobenzene moiety itself. Haberhauer and Kallweit have investigated the twisting direction of the cis-azobenzene moiety by studying the helical chirality linked to a chiral cyclic imidazole tetrapeptide, possessing four asymmetric centers.The axially chiral binaphthyl is rigid in the rod direction, but around the axis has a wide and flexible asymmetric field. Thus, binaphthyl skeletons have been employed in asymmetric organocatalysis,molecular recognition,and chiral doping of liquid crystals. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/chem.201003087

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Axially chiral 2,2'-methylenedioxy-bridged-1,1'-binaphthyls, quaternaphthalenes, and octinaphthalenes were synthesized and their optical properties researched. 2,2'-Methylenedioxy bridges led to a continuous extremely cisoid conformation and subsequent extensive conjugation in the rod direction. Therefore, the absorption and fluorescence regions were red-shifted as the number of naphthalene rings increased. These oligonaphthalenes fluoresced in both solution and the solid state. Furthermore, DFT calculations showed that the LUMO and HOMO of these bridged oligonaphthalenes were spread over a wide range.

DOI： 10.1021/ol100582v

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Novel types of chiroptical switches and memory with non-destructive readout that are entirely optically controlled for molecular devices in solution and neat films.

DOI： 10.1039/c0cc02685a

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

(S,R,S,R,S,R,S)- and (S,R,S,S,S,R,S)-octinaphthalenes were synthesized by oxidative coupling of (S,R,S)-quaternaphthalene, and differences due to axis chirality of (S,R.S,R,S,R,S)-, (S,R,S,S,S,R,S)-, (S,S,S,R,S,S,S)-, and (S,S,S,S,S,S,S)-octinaphthalenes were compared using the R(f) values on TLC, specific optical rotations, (1)H NMR chemical shifts of the hydroxy groups, and CD spectra. A clear CD additivity was found in the Delta(epsilon) values of the (1)L(a) transition around 290 nm, which are proportional to the difference between the numbers of S and R binaphthalene units. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2009.05.040

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

To examine the reversible photoisomerization and subsequent change of asymmetric field, we synthesized optically active 3,3'-disubstituted-1,1'-binaphthyls with an azobenzene moiety. Reflecting the structural change, the specific rotation and circular dichroism underwent significant variations, Under certain conditions, the positive-negative signals were reversible. Furthermore, the magnitude of these changes showed a 3,3'-substituent dependency. Dibenzyloxy or bis(diphenylmethyloxy) derivatives were better suited for sign interconversion of the optical properties. in contrast, the hydroxy group(s) lacked both optical signals and durability.

DOI： 10.1021/jo901030s

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

(S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S,S)-dotriacontanaphthalenes 32A-E alternately possessing butoxy and methoxy side chains were precisely constructed through a bottom-up synthesis, and their absolute configurations and fluorescence quantum yields were determined.

DOI： 10.1021/jo900463t

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized all of the monomethoxycoumarins, 5-alkoxycoumarins and their derivatives, and investigated their nematicidal activity against the phytopathogenic nematode, Bursaphelenchus xylophilus. Among the compounds, 5-ethoxycoumarin showed the highest nematicidal activity. Furthermore, 5-ethoxycoumarin was comparatively harmless against both the brine shrimps, Artemia salina, and the Japanese killifish, Oryzias latipes. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmcl.2008.08.102

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Three oligonaphthalenes with zinc porphyrin and free-base porphyrin moieties were synthesized, in which cascade energy transfer (from naphthalene to free-base porphyrin via zinc porphyrin) was observed when the zinc and free-base porphyrins were close to each other.

DOI： 10.1021/jo800642u

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(Chemical Equation Presented) Tetracosanaphthalenes with diethylaminocarbonylmethoxy side chains were constructed by bottom-up synthesis, and their absolute configurations were determined by an exciton chirality method. © 2007 American Chemical Society.

DOI： 10.1021/jo070343g

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Language：English   Publisher：PHARMACEUTICAL SOC JAPAN  

We have developed an efficient synthesis method for optically active oligonaphthalenes (from 2 mer to 16 mer), which are connected at their 1,4-positions, under oxidative homo coupling with a stoichiometric amount of CuCl2 and amines. The absolute configuration of the newly formed axis bond was determined based on the CD spectra of oligonaphthalenes with 1) two pyrene rings on the central naphthalenes or 2) two tetraphenylporphyrins (TPP) on the top and bottom naphthalenes. The fluorescence quantum yields increased as the number of naphthalene units increased in methoxy derivatives 10-12, and the intramolecular energy transfer quantum yields of bispyrene derivatives 7-9 were around 20% regardless of the number of naphthalene units. Furthermore, the hexadecanaphthalene derivative 4b with two TPPs exhibited a clear exciton coupling over an interchromophore distance to ca. 66 angstrom.

DOI： 10.1248/yakushi.126.779

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Language：English   Publisher：AMER CHEMICAL SOC  

The oxidative homocoupling of optically active binaphthalenes 1a-d with a stoichiometric amount of CuCl2 and amines afforded quaternaphthalenes 2a-d in up to 93% de. The high diastereoselectivities were achieved through three different pathways ( epimerization of the axis together with diastereoselective crystallization, thermodynamic, and kinetic control pathways). The type of side chains on the naphthalene influenced which pathway dominates. Three pathways were applicable to octinaphthalenes ( 8a-d) and hexadecanaphthalene 10a with 46-99% de. The absolute configuration of the newly formed axial bond was determined by ( 1) X-ray crystallographic analysis, ( 2) transformation to known compounds 15 and 16, ( 3) CD spectra of oligonaphthalenes with two pyrene rings as exciton parts, and ( 4) the shift values in C-13 NMR spectra of C-13-enriched derivatives 29-31 toward chiral shift reagent Eu(+tfc)(3).

DOI： 10.1021/jo060974v

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Hexadecanaphthalenes (S, S, S, S, S, S, S, S, S, S, S, S, S, S, S)-4b and ( S, S, S, S, S, S, S, R, S, S, S, S, S, S, S)-4b that possess two tetraphenylporphyrins (TPP) on the upper and lower naphthalene rings were synthesized. Long-range exciton-coupled CD in the Soret region of TPP (about 66 angstrom) was observed.

DOI： 10.1021/ol060843g

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Several 3-alkylphenols including 3-undecylphenol, which was isolated from a Sumatran rainforest plant, were synthesized to investigate their antinernatodal activity against the phytopathogenic nematodes, Bursapherencus xylophilus. A three-step synthesis involving the treatment of 2-cyclohexen-1-one with the Grignard reagent, oxidation of the resulting 1-alkyl-2-cyclohexen-1-ol and subsequent aromatization of 3-alkyl-2-cyclohexen-1-one successfully afforded such phenols. Among the 3-alkylphenols, 3-nonylphenol showed the highest activity, while 3-decylphenol and 3-undecylphenol also showed high activity.

DOI： 10.1271/bbb.68.2398

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Publishing type：Research paper (scientific journal)  

DOI： 10.1128/JB.74.1.94-100.1957

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