Fujita Masahiro

A series of alternating copolymers consisting of chiral thiophene and fluorene, poly[9,9-dihexylfluorene-alt-(3-{2-[(S)-(+)-1-methyloctyloxy]ethyl}thiophene)] (P1), and poly[9,9-dihexylfluorene-alt-(3-{2-[(S)-(+)-1-methyloctyloxy]ethyl}-2,2'-bithiophene)] (P2), were synthesized by Suzuki coupling method. P1 and P2 were characterized by (1)H NMR spectra and elemental analyses. Both of the copolymers showed clear solvatochromism and circular dichroism in methanol/chloroform mixed solutions. These two polymers had different spacer lengths between the chiral side chains along the main chain. and accordingly the circular dichroism spectra were apparently different. (C) 2009 Elsevier B.V. All rights reserved.

Poly[9,9-dihexylfluorene-co-(benzothiazol-2-yl)thiophene-co-9,9'-spirobifluorene] (PF(x)B(y)S(z)) were synthesized by palladium-catalyzed Suzuki coupling reaction. PE(x)B(y)S(z) were characterized by FT-IR,elemental analysis, and (1)H NMR. All the copolymers showed decomposition temperatures above 400 degrees C and glass transition points above 180 degrees C. suggesting that these materials had excellent thermal stability. As the benzothiazolylthiophene content in copolymers was increased, the band gaps of copolymers decreased. All the copolymers exhibited fluorescence peaks in the visible region, and the energy transfer from fluorene to benzothiazolylthiophene units were observed. (C) 2009 Elsevier B.V. All rights reserved.

Novel lead iodide-based layered perovskite compounds, which contain fullerene derivatives, N-methyl-2-(4-ammoniumphenyl)-fulleropyrrolidine iodide (AmPF) and N-(n-dodecyl)-2-(4-ammoniumphenyl)fulleropyrrolidine iodide (C12AmPF), in their organic layers were fabricated as thin solid films by spin-coating. The XRD profiles showed that (AmPF)Pbl(4) molecules were arranged in a closer-packing form, compared with (C12AmPF)Pbl(4). The photoluminescence spectra of thin films suggested the presence of energy transfer between C(60) moiety and lead(II) iodide layers, which led to the disappearance of fluorescence peak at 517 nm and the appearance of a new fluorescence peak at 780 nm.(AmPF)Pbl(4) and (C12AmPF)Pbl(4) films exhibited photoconductivity when ultraviolet light was irradiated, and the photocurrent values with applying 1.0 V bias voltage were 1.77 mu A and 1.48 x 10(-2) mu A, respectively. (C) 2009 Elsevier B.V. All rights reserved.

A series of salts, some of which are ionic liquids, are prepared from cations and anions drawn from Active Pharmaceutical Ingredients (APIs) and Generally Recognized As Safe (GRAS) materials. Using the solid-state structures of the crystalline salts as a basis, an anti-crystal engineering approach to the preparation of "Active Ionic Liquids" (AILs) is explored.

This article reports for the first time the rapid one-pot solvent. free synthesis of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF(4)), a major ionic liquid, in good yields (87%) after 30 min of microwave irradiation with microwaves at a frequency of 5.8 GHz in a batch-mode reactor. By contrast, the yields of [bmim]BF(4) are about 3-to-4-fold smaller when using 2.45-GHz microwave radiation and oil bath heating: 28% and 21%, respectively, under otherwise identical conditions. This further shows the advantage(s) of the 5.8-GHz microwave radiation and the accompanying apparatus as a novel synthetic tool reported in some detail elsewhere {Org. Process Res. Dev.. 2008, 12, 257-263}. The three synthetic methods (viz., 5.8-GHz and 2.45-GHz microwave heating, and oil bath heating) were examined in reactors used in both the batch and reflux modes. In the latter mode, the yields of [bmim]BF(4) were less than 10% even after a 60-min reaction period. The dependence of the synthesis on the frequency of the microwave radiation is discussed in terms of the chemical yields of the product and the dielectric factors of each substrate in the synthesis mixtures composed of 1-methylimidazole, 1-chlorobutane. and sodium tetrafluoroborate.

Lipase-catalyzed polymerizations of L-lactide were carried out in four kinds of ionic liquids (ILs) in order to investigate the effect of ILs on the conversion, molecular weight, and yield of the obtained poly(lactide) (PLLA). PLLA could be synthesized in ILs of 1-butyl-3-methylimidazolium ([C(4)mim]) except in [C(4)mim][N(CN)(2)]. While the number-average molecular weight (M-n) of the PLLA obtained in [C(4)mim][PF6] was below 4000 g mol(-1) and the yield was below 10%, the M-n and yield of the PLLA obtained in [C(4)mim][BF4] reached 55000g mol(-1) and 35%, respectively. The M-n values of PLLAs in the ILs were clearly higher than those of PLLAs obtained in bulk and in toluene (< 44000 g mol(-1)). The polymerization in the ILs proceeds even at lower temperatures as compared with that in bulk. The effect of lipase content on the M-n of PLLA was also investigated. When [C(4)mim][BF4] was used as the solvent, the highest M,, was obtained at a lipase content of 10wt%,. In the case of [C(4)mim] [NTf2], the most suitable lipase content depended on the polymerization temperature. [C(4)mim][BF4] was suitable to obtain higher molecular weight PLLA and higher polymer yield at lower lipase contents. Copyright (C) 2008 John Wiley & Sons, Ltd.

Poly(L-lactide) (PLLA) has been synthesized by ring-opening bulk polymerization Of L-lactide in porous hydroxyapatite (HAp) matrix without any additional catalyst, and this hybridizing process directly provided artificial bone materials. The obtained PLLA/HAp composites had enough mechanical properties with a bending strength of 53.7MPa, which was 2.3 times stronger than porous HAp, and showed excellent biocompatibility for clinical applications.

Choline dihydrogen phosphate ([N-1.1.1.2OH]DHP) and 1-butyl-3-methylimidazolium dihydrogen phosphate ([C(4)mim]DHP) were synthesized as a new class of proton-conducting ionic plastic crystals. Both [N-1.1.1.2OH]DHP and [C(4)mim]DHP showed solid-solid phase transition(s) and showed a final entropy of fusion lower than 20 J K-1 mol(-1) which is consistent with Timmerman's criterion for molecular plastic crystals. The ionic conductivity of [N-1.1.1.2OH]DHP was in the range of 10(-6) S cm(-1) -10(-3) S cm(-1) in the plastic crystalline phase. On the other hand, the ionic conductivity of [C(4)mim]DHP showed about 10(-5) S cm(-1) in the plastic crystalline phase. [N-1.1.1.2OH]DHP showed one order of magnitude higher ionic conductivity than [C(4)mim]DHP in the temperature range where the plastic phase is stable. (c) 2007 Elsevier B.V. All rights reserved.

We have synthesized two kinds of new Lewis-base ionic liquids (ILs); one is based oil the relatively strong Lewis basic acetate anion, and the other is a salt composed of a mono-alkylated diamine such that the Lewis base site is incorporated in the cation. I-Octyl-4-aza-1-azonia-bicyclo[2.2.2]octane bis(trifluoromethinesulfonyl)amide, [C(8)dabco]TFSA, and N-butyl-N-methylpyrrolidinium acetate, [P-1,P-4]OAc, melted into fluid liquids at 26 and 81 degrees C, respectively. The thermal decomposition of [p(1,4)]OAc started at around 150 degrees C, whereas the thermal stability of [Csdabco]TFSA was almost equal to that of typical TFSA-based ILs in spite of the Lewis base site. This suggests that if the Lewis base site is incorporated into the cation the IL call maintain higher thermal stability. In addition, as a further result of the presence of the basic nitrogen, [C8dabco]TFSA can dissolve hydrated Cu(NO3)(2) whereas the other TFSA-based ILs cannot. (c) 2006 Elsevier Ltd. All rights reserved.

A new Lewis-base ionic liquid (IL) based on mono-charged 1,4-diazabicyclo[2.2.2]octane (dabco) was synthesized and its thermal and electrochemical behaviour was characterized. The dabco-based IL with bis(trifluoromethanesulfonyl)amide (TFSA) anion melts at 76 degrees C when the N-substituted alkyl chain length is 2. The dabco-based IL showed a wide electrochemical window of over 4 V ranging from -3.5 to +1.5 V vs. Fc/Fc(+) and was able to deposit and strip lithium from a nickel substrate at reasonable efficiency. (c) 2006 Elsevier B.V. All rights reserved.

2-Heptadecylimidazole (a) neutralized with a series of acids showed good thermal stability. The decomposition temperature of most salts exceeded 200 degrees C. Among these, a neutralized with HBF4 showed enantiotropic liquid crystalline phase. Higher ionic conductivity and lower activation energy were found for the salt in the liquid crystalline phase. The a neutralized with HBF4 was mixed with 11 mol% a to introduce the proton acceptor sites in the assembled a. The mixture showed a monotropic liquid crystalline phase. High ionic conductivity and low activation energy were also seen in the monotropic liquid crystalline phase.

Two types of thermotropic smectic phase and of anisotropic ion conduction were observed in an amphiphilic ionic liquid, N-ethyl-N'-dodecylimidazolium dodecyl sulfonate/lithium tetrafluoroborate mixture.

Aliphatic and alicyclic ammonium inner salts containing an ether bond were prepared as a new family of zwitterionic liquids. Ether bond is not only effective for lowering melting points of ammonium-type zwitterions but also interesting to realize unique solid-solid transition.

Novel ionic liquids (ILs) composed of azole type cation and anion were prepared. Triazole and tetrazole were coupled with 1-ethyl-3-methylimidazolium hydroxide. Obtained tetrazole salt was liquid at room temperature showing only glass transition temperature at −89 °C. The ionic conductivity reached to 8.9 × 10⁻³ S cm⁻¹ at room temperature reflecting low viscosity of 42.5 cP at 25 °C. This is the first report on the ILs based on only azole type ions.

We have prepared polymer gel electrolytes with alkali metal ionic liquids (AMILs) that inherently contain alkali metal ions. The AMIL consisted of sulfate anion, imidazolium cation, and alkali metal cation. AMILs were mixed directly with poly(3-sulfopropyl acrylate) lithium salt or poly(2-acrylamido-2-methylpropanesulfonic acid) lithium salt to form polymer gels. The ionic conductivity of these gels decreased with increasing polymer fraction, as in general ionic liquid/polymer mixed systems. At low polymer concentrations, these gels displayed excellent ionic conductivity of 10(-4) to 10(-3) S cm(-1) at room temperature. Gelation was found to cause little change in the Li-7 diffusion coefficient of the ionic liquid, as measured by pulse-field-gradient NMR. These data strongly suggest that the lithium cation migrates in successive pathways provided by the ionic liquids. (C) 2004 Elsevier Ltd. All rights reserved.

The ionic conductivity of highly deproteinized liquid natural rubber having epoxy group (LEDPNR) mixed with alkali metal salts was investigated through impedance analysis to clarify the effect of proteins present in the rubber. The LEDPNR, thus used, was prepared from depolymerization of epoxidized natural rubber (ENR) latex, which was deproteinized by incubation of the latex with proteolytic enzyme and surfactant. The ionic conductivity of the resulting LEDPNR was dependent upon the alkali metal salts, where the ionic conductivity of LEDPNR/bis(trifluoromethane sulfonyl)imide (LiTFSI) was higher than that of LEDPNR/lithium perchlorate (LiClO4). The difference in the ionic conductivity was attributed to the solubility of the salts through both high-resolution solid-state C-13 nuclear magnetic resonance (NMR) spectroscopy and measurements of spin-lattice relaxation time. The ionic conductivity of LEDPNR/LiTFSI was also dependent upon concentration of LiTFSI and the conductivity reached the highest value at 20 wt.%, which was different from the monotonic increase in the ionic conductivity of liquid ENR prepared from untreated natural rubber latex. (C) 2004 Elsevier B.V. All rights reserved.

Ionic liquid-type polymer brushes having different hydrocarbon (HC) chain lengths between polymerizable group and imidazolium ring were synthesized. When the carbon number of HC chain was 6, the ionic liquid-type polymer brush exhibited the highest ionic conductivity of 1.37 x 10(-4) S cm(-1) at 30 degreesC reflecting low T-g of -60 degreesC. Moreover, for the first time, we succeeded in obtaining transparent and flexible films without considerable decrease in the ionic conductivity as compared with that of corresponding monomers by using suitable cross-linkers. The most ion conductive (1.1 x 10(-4) S cm(-1) at 30 degreesC) film was obtained when tetra(ethylene glycol)diacrylate was used 0.5 mol% to ionic liquid monomer as the cross-linker. This film is one of excellent conductive films among single-ion conductive materials. (C) 2004 Elsevier Ltd. All rights reserved.

Anisotropic ion-conductive materials have been prepared by self-assembly of a conventional ionic liquid and a hydroxyl-terminated liquid crystal. These assemblies form phase-segregated layered structures on the nanometer scale. Anisotropic ionic conductivities along the direction parallel and perpendicular to the layer have been successfully measured for the sample forming oriented monodomains. The ionic conductivity parallel to the layer (sigma(i//)) is higher than that perpendicular to the layer (sigma(iperpendicular to)). The maximal anisotropy (sigma(i//)/sigma(iperpendicular to)) is 2.6 x 10(3) at 37degreesC in the smectic B phase.

We describe the behavior of the conductivity, viscosity, and vapor pressure of various binary liquid systems in which proton transfer occurs between neat Bronsted acids and bases to form salts with melting points below ambient. Such liquids form an important subgroup of the ionic liquid (IL) class of reaction media and electrolytes on which so much attention is currently being focused. Such "protic ionic liquids" exhibit a wide range of thermal stabilities. We find a simple relation between the limit set by boiling, when the total vapor pressure reaches one atm, and the difference in pK(a) value for the acid and base determined in dilute aqueous solutions. For DeltapK(a) values above 10, the boiling point elevation becomes so high (>300 degreesC) that preemptive decomposition prevents its measurement. The completeness of proton transfer in such cases is suggested by the molten salt-like values of the Walden product, which is used to distinguish good from poor ionic liquids. For the good ionic liquids, the hydrogen bonding of acid molecules to the proton-transfer anion is strong enough that boiling points, but not melting points, may maximize at the hydrogen-bonded dianion composition. High boiling liquids of this type constitute an interesting class of high-temperature protonic acid that may have high-temperature fuel cell applications.

As a further example of the extraordinary solvent powers of ambient temperature molten salts (ATMS or "ionic liquids'') we demonstrate that lithium thiophosphate glasses, well known for their unicationic conduction mechanism, and high ambient conductivity, dissolve in the ATMS ethylmethylimidazolium tetrafluoroborate up to 30 mol %. Remarkably, the conductivity of this solution is higher than that of a solution of the same lithium salt content made with the salt lithium TFSI [bis(trifluoromethanesulfonyl)imide] which bestows high conductivity on most other solvents. The glass-saturated melt has almost the same conductivity as the glass itself. However their glass temperatures differ by some 200 K so it is clear that the solution retains little if any of the decoupled Li+ conduction mechanism of the glass. It may nevertheless make a suitable electrolyte for lithium cells of a novel kind. Since the ionic liquids may be incorporated in polymer gel electrolytes without significant loss of conductivity, the present solutions may prove valuable for solid-state electrochemical device applications. (C) 2003 The Electrochemical Society.

Modification of cytochrome c (cyt.c) by poly(ethylene oxide) (PEO) chains enabled the protein soluble in 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ionic liquid without denaturation. However, as the solution was full of ions, suitable supporting electrolyte (KCl) was essential for the electron transfer reaction of cyt.c in the ionic liquid to attain adequate ion size for the active center.