Jun Wada

Nippon Paint Co., Ltd., Ōsaka, Ōsaka, Japan

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Publications (11)50.02 Total impact

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    ABSTRACT: TEMPO-containing 7-oxanorbornene monomers 1–4 (TEMPO = 2,2,6,6-tetramethylpiperidine-1-oxy) were synthesized and polymerized via ring-opening metathesis using a ruthenium carbene catalyst. Monomers 1 and 3 gave polymers with number-average weights of 80 100 and 112 200 in 85 and 96% yields, respectively, whereas monomers 2 and 4 did not provide high molecular weight polymers. Poly(1) and poly(3) were soluble in common solvents including CHCl3, CH2Cl2 and THF, while insoluble in hexane, diethyl ether and MeOH. They were thermally stable up to ca. 240 °C according to the TGA measurements in air. The secondary batteries utilizing the present polymers as cathode-active material demonstrated reversible charge/discharge processes, whose discharge capacities were 107 and 92.8 A h/kg, and displayed excellent high-rate charge and discharge properties. These cells demonstrated excellent cycle life, e.g., the discharge capacities of poly(1) and poly(3) showed less than 10% decrements even after 100 cycles.Graphical abstract
    No preview · Article · Jan 2009 · Polymer
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    ABSTRACT: A group of ferrocene-containing polymers were synthesized from vinylferrocene, ethynylferrocene and 1,1'-dibromoferrocene, and properties of the formed polymers were examined to clarify their potential as a new class of cathode-active, charge-storage materials for rechargeable batteries. Vinylferrocene polymerized with 2,2'-azoisobutyronitrile (AIBN) to give a polymer with number-average molecular weights of 2200-5100 g . mol(-1) in 12-41% yields, while ethynylferrocene and 1,1'-dibromoferrocene polymerized with Rh catalysts and by step-growth mechanism, respectively, to provide insoluble polymers in 71-96% yields. The capacities of organometallic rechargeable cells fabricated with poly(vinylferrocene), poly(ethynylferrocene), and poly(ferrocene) reached 105, 105, and 9 5 Ah . kg(-1), respectively. In particular, poly(vinylferrocene) displayed completely reversible charge/discharge processes featuring a constant voltage of around 3.5 V.
    No preview · Article · Dec 2008 · Macromolecular Rapid Communications
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    ABSTRACT: We report here the first example of organic radical battery with DNA. Though there is a growing interest in DNA/cationic-lipid complexes as promising gene delivery vehicles, few efforts have been focused on the use of such complexes as advanced materials for organic optoelectronic applications. The present article describes how substitution of the sodium counter cation of DNA with cationic amphiphilic lipid(1-4) provided novel DNA-lipid complexes that contain TEMPO radicals, in which the actual mole ratio of phosphate to lipid was 1:0.84 to 1:0.16. All the TEMPO-containing DNA-lipid complexes displayed reversible two-stage charge/discharge processes, the discharge capacities of which were 40.5-60.0 A h kg(-1). In particular, the capacity of a DNA-lipid(3)-based cell reached 60.0 A h kg(-1), which corresponds to 192 % relative to its theoretical value for the single-electron one-stage process, indicating a two-electron process.
    No preview · Article · Apr 2008 · Chemistry
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    ABSTRACT: Ethyl cellulose derivatives [EC-T and EC-P] and cellulose acetate derivatives [CA-T and CA-P] carrying TEMPO or PROXY radicals (TEMPO = 2,2,6,6-tetramethyl-1-piperidinyloxy, PROXY = 2,2,5,5-tetramethyl-1-pyrrolidinyloxy) were synthesized with moderate number-average molecular weights of 62 400–126 000 in 84–88% yield by the reaction of 4-carboxy-TEMPO or 3-carboxy-PROXY with residual hydroxyl group of ethyl cellulose or cellulose acetate. All the free radical-containing cellulose derivatives demonstrated reversible charge/discharge processes, whose discharge capacities were 42.8–61.1 A h/kg. In particular, the CA-T-based cell displayed two-stage discharge process, and the first-stage discharge capacity reached 29.5 A h/kg which corresponds to 74% of its theoretical value, and that of the total capacity was 61.1 A h/kg which approaches up to 153% of the theoretical value for one-electron redox reaction.
    No preview · Article · Mar 2008 · Polymer
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    ABSTRACT: TEMPO-containing norbornene monomers 1-8 (TEMPO = 2,2,6,6-tetramethylpiperidine-1-oxy) were synthesized and polymerized via ring-opening metathesis using a ruthenium-carbene catalyst. The TEMPO moiety did not inhibit the polymerization, and the monomers gave corresponding polymers in good to high yields. Poly(2) and poly(3) were soluble in common solvents and possessed high molecular weight, while other polymers were insoluble. The resulting polymers were thermally stable up to ca. 240 degrees C according to TGA measurements in air. In the case of poly(1)-poly(3), the charge/discharge capacities of the polymer-based cells were largely dependent on the spatial arrangement of the two TEMPO moieties on each repeating unit. Quite interestingly, the capacity of the poly(2)-based cell reached its theoretical value (109 A h/kg), and a large capacity (> 90 A h/kg) was retained even at high current densities up to 6 A/g, indicating the possibility of very fast charging (within 1 min). The cells utilizing the present polymers as cathode-active materials demonstrated excellent cycle life; e.g., the discharge capacities of poly(2) and poly(3) showed no more than 10% decrement even after 400 cycles.
    No preview · Article · Feb 2008 · Macromolecules
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    ABSTRACT: 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO)- and 2,2,5,5-tetramethyl-1-pyrrolidinyloxy (PROXYL)-containing (R)-1-methylpropargyl TEMPO-4-carboxylate (1), (R)-1-methylpropargyl PROXYL-3-carboxylate (2), (rac)-1-methylpropargyl PROXYL-3-carboxylate (3), (S)-1-propargylcarbamoylethyl TEMPO-4-carboxylate (4), and (S)-1-propargyloxycarbonylethyl TEMPO-4-carboxylate (5) (TEMPO, PROXYL) were polymerized to afford novel polymers containing the TEMPO and PROXYL radicals at high densities. Monomers 1–3 and 5 provided polymers with moderate number-average molecular weights of 8200–140,900 in 49–97% yields in the presence of (nbd)Rh+[η6-C6H5B−(C6H5)3], whereas 4 gave no polymer with this catalyst but gave polymers possessing low Mn (3800–7500) in 56–61% yield with [(nbd)RhCl]2-Et3N. Poly(1), poly(2), and poly(4) took a helical structure with predominantly one-handed screw sense in THF and CHCl3 as well as in film state. The helical structure of poly(1) and poly(2) was stable upon heating and addition of MeOH, whereas poly(4) was responsive to heat and solvents. All of the free radical-containing polymers displayed the reversible charge/discharge processes, whose capacities were in a range of 43.2–112 A h/kg. In particular, the capacities of poly(2)–poly(5)-based cells reached about 90–100% of the theoretical values regardless of the secondary structure of the polymer, helix and random. Poly(1), poly(2), and poly(4) taking a helical structure exhibited better capacity tolerance towards the increase of current density than nonhelical poly(3) and poly(5) did. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5431–5445, 2007
    No preview · Article · Dec 2007 · Journal of Polymer Science Part A Polymer Chemistry
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    ABSTRACT: The 2,2,6,6-tetramethyl-1-piperidinoxy (TEMPO)-containing acetylenic monomers HC[triple bond]CC(6)H(3)-p,m-(CONH-4-TEMPO)(2) (1), HC[triple bond]CC(6)H(3)-p,m-(COO-4-TEMPO)(2) (2), (S,S,S,S)-HC[triple bond]CC(6)H(3)-p,m-[CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO)](2) (3), (S,S)-HC[triple bond]CC(6)H(4)CO-NHCH{COO-(4-TEMPO)}CH(2)COO-(4-TEMPO) (4), HC[triple bond]CC(6)H(4)-p-OCO-4-TEMPO (5), HC[triple bond]CCH(2)C(CH(3))(CH(2)OCO-4-TEMPO)(2) (6), HC[triple bond]CCH(2)NHCO-4-TEMPO (7), and HC[triple bond]CCH(2)OCO-4-TEMPO (8) were polymerized to afford novel polymers containing the TEMPO radical at high densities. Monomers 1, 3-6, and 8 provided polymers with average molecular weights of 10 000-136 500 in 62-99 % yield in the presence of a rhodium catalyst, whereas monomers 2 and 7 gave insoluble polymers in 100 % yield. The formed polymers were thermally stable up to approximately 274 degrees C according to thermogravimetric analysis (TGA). All the TEMPO-containing polymers demonstrated reversible charge/discharge processes, whose discharge capacities were 21.3-108 A h kg(-1). In particular, the capacity of poly(1)-, poly(4)-, and poly(5)-based cells reached 108, 96.3, and 89.3 A h kg(-1), respectively, which practically coincided with their theoretical values.
    No preview · Article · Sep 2007 · Chemistry
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    ABSTRACT: We fabricated a rechargeable molecular cluster battery, based on a cathode active material, [Mn(12)O(12)(CH(3)COO)(16)(H(2)O)(4)]. The charging-discharging experiments revealed rechargeable battery performance with a capacity of ca. 90 A h kg(-1), while the first discharging process exhibited an extremely high value of 200-250 A h kg(-1).
    No preview · Article · Sep 2007 · Chemical Communications
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    ABSTRACT: PROXYL-containing propargyl ester HCCCH2OCO-3-PROXYL (1), N-propargylamide HCCCH2NHCO-3-PROXYL (2), 1-pentyne-4,4-dimethyl ester HCCCH2C(CH3)(CH2OCO-3-PROXYL)2 (3), and norbornene diester monomers NB-2,3-exo,exo-(CH2OCO-3-PROXYL)2 (4), NB-2,3-endo,endo-(CH2OCO-3-PROXYL)2 (5), and NB-2,2-(CH2OCO-3-PROXYL)2 (6) (NB = norbornene, PROXYL = 2,2,5,5-tetramethyl-1-pyrrolidinyoxy) were polymerized to afford novel polymers containing the PROXYL radical at high densities. While 1 and 2 provided polymers with number-average molecular weights of 3300−29 800 in 60−65% yields in the presence of a Rh catalyst, monomers 4−6 gave polymers with number-average molecular weights up to 209 000−272 000 in 90−94% yields with a Ru catalyst. The formed polymers were thermally stable up to ca. 220 °C according to TGA and soluble in common organic solvents including toluene, CHCl3, and THF. Poly(1), poly(2), and poly(4)−poly(6) hardly exhibited absorption above 400 nm, which corresponds with their very light color. The oxidation/reduction gaps in the cyclic voltammograms of the present polymers were as small as 0.072−0.092 V, indicating large electrode reaction rates. All the PROXYL-containing polymers demonstrated the reversible charge/discharge processes, whose capacities were larger than 85 A h/kg. In particular, the maximum capacity of poly(1)- and poly(4)-based cells reached 117 and 107 A h/kg, which practically coincided with the theoretical capacity values (119 and 109 A h/kg, respectively).
    No preview · Article · Apr 2007 · Macromolecules
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    ABSTRACT: 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO)containing N-propargylamide HC=CCH2NHCO-4-TEMPO (1), propargyl ester HC=CCH2OCO-4-TEMPO (2), phenylacetylene derivative HC=CC6H3-3,4-(CO2-4-TEMPO)(2) (3), and norbornene diester monomers, NB-2,3-exo,exo-(CH(2)OCO4-TEMPO)(2) (4), NB-2,3-endo,exo-(COO-4-TEMPO)(2) (5a), NB-2,3-endo,endo-(COO-4-TEMPO)(2) (5b) (NB = norbornorbornene, TEMPO= 2,2,6,6-tetramethyl-1-piperidinyloxyl) were synthesized and polymerized with rhodium and ruthenium catalysts. Monomers 2, 5a, and 5b gave polymers with number-average molecular weights of 47000-185000 in 59-100% yields, while 1, 3, and 4 gave polymers insoluble in common organic solvents in 88-100% yields. The capacities of cells fabricated with poly(l), poly(2), and poly(3) were 67, 82, and 23 Ah . kg(-1) based on the weight, respectively. The capacity of poly(5a)-based cell reached the theoretical value (109 Ah . kg(-1)) of the polymer.
    No preview · Article · Aug 2006 · Macromolecular Rapid Communications
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