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  • Polymer and Materials Science  (6)
  • 1
    Electronic Resource
    Electronic Resource
    Hydrophobic environmental effects on oxygenation of polymeric hemochrome in aqueous solution (1975)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 176 (1975), S. 2251-2261 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die reversible Oxygenierung des synthetischen polymeren Pyridin-Häm-Komplexes wurde bei Zimmertemperatur in wäßriger Lösung untersucht. Das polymere Hämochrom wurde durch die Koordination des partiell quartären Poly(4-vinylpyridin)s (QPVP) an der axialen Position des Protohäms in Wasser synthetisiert. Die Gleichgewichtskonstanten von Hämichrom und Hämochrom waren 2,60·102 und 2,77·104 dm3mol-1, und die Koordinationszahl der axialen Liganden (Pyridingruppen) war sowohl im Fall von Hämichrom als such im Fall von Hämochrom ca. 1,0.Die Kinetik der elementaren Prozesse der Oxygenierung, d. h. der “Adsorption von O2” bzw. der “irreversiblen Oxydation des resultierenden Sauerstoff-Komplexes” wurde als Funktion des lokalen Feldes um das Häm herum untersucht. Die Geschwindigkeit des irreversiblen Oxydationsprozesses des Häm-Sauerstoff-Komplexes wurde durch Hydrophobieren der Umgebung des Häm stark verringert. Diese Effekte wurden ausgelöst durch die stärkere Knäuelung von QPVP-Molekülen durch die Addition von Salzen {Natriumchlorid, Natriumdodecylsulfat und Poly[1-(natrium sulfonatophenyl)-äthylen]} oder durch die Komplexierung von QPVP mit Polymethacrylsäure. Das Redoxpotential des zentralen Metallions des Häms wurde infolge der Zunahme der Hydrophobie um das Häm verringert. Andererseits war die Geschwindigkeit des Adsorptionsprozesses an-nähernd konstant und unabhängig von der Veränderung der Mikroumwelt um das Ham.
    Notes: The reversible oxygenation of a synthetic polymeric pyridine-hemochrome was studied in aqueous solution at room temperature. The polymeric hemochrome was synthesized by coordination of partially quaternized poly(4-vinylpyridine), (QPVP), to the axial site of protoheme in water. The equilibrium constants of hemichrome and hemochrome were 2,60.102 and 2,77.104dm3 mol-1, respectively, and the coordination number of axial ligands (pyridine groups) both in the complexation of heme and hemin was approximately 1,0.The kinetics of the elementary processes of oxygenation, i.e. “adsorption of O2” and “irreversible oxidation of the resulting oxygen complex”, were studied as a function of the local field around heme. The rate of the irreversible oxidation process of the heme oxygen complex was greatly lowered as a result of situating the active site of heme inside the hydrophobic environment formed by shrinking QPVP with adding a salt {sodium chloride, sodium dodecylsulfate, and poly[1-(sodium sulfonatophenyl)-ethylene]} or by complexing QPVP with poly(methacrylic acid). The redox potential of the central metal ion of heme was lowered by increasing the hydrophobicity around heme. On the other hand, the rate of the adsorption process was approximately constant, regardless of the microenvironmental change around heme.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1975.021760807
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  • 2
    Electronic Resource
    Electronic Resource
    Reversible oxygenation of heme bound to polyvinylpyridine and polyvinylimidazole (1974)
    New York : Wiley-Blackwell
    Biopolymers 13 (1974), S. 2147-2159 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The interaction between heme bound to poly-4-vinylpyridine (PVP) or poly-N-vinyl-2-methylimidazole (PVMI) and molecular oxygen (O2) was studied. In this paper, the reactions of some types of heme with O2 in organic solvents, particularly in N,N-dimethylformamide (DMF) were discussed. The free heme not bound to an axial base was easily oxidized irreversibly to hemin in DMF with bubbled O2. The hemochromogens complexed with pyridine, imidazole, or their polymeric derivatives such as PVP and PVMI bound O2 to one of the axial coordination sites. The characteristic absorption band assignable to the resulting oxygenated heme was observed at 402 nm. This absorption band could be changed back to the characteristic band of the reduced hemochromogen at 418 nm by removing O2 dissolved in the DMF solution by a vacuum or by a stream of nitrogen. Thus, the hemochromogens bound to the synthetic polymers were found to adsorb and desorb O2 reversible in DMF.When the polymeric ligands were used, the equilibrium constants in the complexation of heme with these polymers were about 102 times as large as those of the corresponding monomeric ligands. The oxygenation rates and the capacities of O2 of the polymeric hemochromogens were larger than those of the monomeric hemochromogens. In addition, the oxygenation rate of the polymer complex was changeable owing to the conformational change of the polymeric ligand; this rate increased about ten times under the optimal condition.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1974.360131015
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  • 3
    Electronic Resource
    Electronic Resource
    Synthesis and polymerization of various vinyl-type monomers containing the pyrrole ring (1973)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 11 (1973), S. 853-872 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinyl-type monomers containing the pyrrole ring, such as 2-vinylpyrrole (2-VPyrr), N-(pyrrol-2-yl)methylacrylamide (PMA), N-methyl, N-(pyrrol-2-yl)methylacrylamide (MPMA), 2-allylpyrrole (2-AP), β-(pyrrol-1-yl)ethyl vinyl ether (PEVE), 2-diallyl-aminomethylpyrrole (DAMP), and 3-(2-pyrrolylmethyleneimino)propene-1 (PIP) were synthesized by various reactions involving characteristic properties of the pyrrole ring. Radical homopolymerizations and copolymerizations of these monomers were studied. In the homopolymerization of conjugated monomers such as 2-VPyrr and PMA, chain transfer to the pyrrole-containing monomer was remarkable but not degradative. The copolymerization parameters, that is, the values of r1, r2, Q1, and e1 of 2-VPyrr, were determined to be 0.066, 0.69, 5.53, and -1.36, respectively in the copolymerization of 2-VPyrr (M1) with MMA (M2). The Q and e values of the monomers containing a heteroaromatic ring such as 2-vinylpyrrole, 2-vinylfuran, and 2-vinylthiophene were evaluated by the molecular orbital theory. The e value of PMA was found to be negative (-0.64) in the copolymerization with styrene, although e for acrylamide derivatives is generally positive. This may be explained by the intermolecular hydrogen bonding between the carbonyl group and NH group of PMA. That is, attraction or polarization of π-electrons in the vinyl group of PMA is weakened by such hydrogen bonding. From the results of copolymerization of 2-AP with various comonomers, the comonomers could be classified into three categories: class a monomers, in which both Q and e values are largely positive, can copolymerize with 2-AP; class b monomers, having small e values, homopolymerize and can not copolymerize with 2-AP; class c monomers, in which both Q and e values are small. The Q and e values of the comonomer must be largely positive in order to permit copolymerization with an allyl-type monomer.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1973.170110412
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  • 4
    Electronic Resource
    Electronic Resource
    Interpolymer complex between poly(ethylene oxide) and poly(carboxylic acid) (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 13 (1975), S. 1505-1514 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An interpolymer complex was prepared by mixing aqueous solutions of poly(ethylene oxide) (PEO) and of a poly(carboxylic acid), i.e., poly(acrylic acid)(PAA), poly(methacrylic acid)(PMAA), or styrene-maleic acid copolymer(PSMA). The complexation mechanism was discussed on the basis of results of such experimental methods as viscosity, potentiometric titration, and turbidimetry. The hydrogen bond is primarily involved in these complexations, but the influence of hydrophobic interaction on complexation can not be ignored. If the degree of dissociation α of carboxylic acid or the degree of polymerization Pn of PEO was perceptibly changed, a stable complex was obtained at about α 0.1 or Pn(PEO) = 40 for PMAA, 200 for PAA. This fact indicates that more than a definite number of binding sites are necessary for a stable interpolymer complex to be formed and that cooperative interaction among active sites plays an important role in complex formation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.170130703
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  • 5
    Electronic Resource
    Electronic Resource
    Radical polymerization of metal-coordinated monomers with ligands of pyrrole-containing schiff bases (1974)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 1243-1255 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copper complexes and the cobalt complex with the ligand of 3-(2-pyrrolylmethyl-enimino)propene-1 (PIP) or p-(2-pyrrolylmethylenimino)styrene (PIS) were synthesized and homopolymerizations and the copolymerization with styrene, acrylonitrile, methyl methacrylate and acrylic acid studied. In the polymerization of chelate monomers, inhibition of radical polymerization by the central metal ion was observed, but the chelate polymer could be obtained only if the initiator was present in higher concentrations in the feed. It is considered that the strength of inhibition depends on the electronic configuration of d-orbitals of the central metal ion. The initiation mechanism of the cupric chelate monomer may be reduction of the metal ion by the redox reaction with a primary radical via the intramolecular electron transfer through the π-conjugated system of the ligand prior to the propagation step. This mechanism was verified by studying the redox reaction of various copper complexes with DPPH. In the system of the copper complex containing PIS and acylic acid the alternating copolymer could be obtained at any mole fraction of monomer mixture in feed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1974.170120610
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  • 6
    Electronic Resource
    Electronic Resource
    Polymerization of α-amino acid N-carboxy anhydrides initiated by histamine in N,N-dimethylformamide (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 13 (1975), S. 1747-1756 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of α-amino acid N-carboxy anhydrides (NCAs) initiated by 4-aminoethylimidazole (histamine) was studied in order to synthesize poly(amino acids) containing an imidazole nucleus at the end of polymer chain. On the basis of the kinetical measurements, it was found that the rate of polymerization is proportional to the first order in both NCA and initiator concentrations and that the initiation reaction is predominantly caused by the primary amine with the highest basicity in a histamine molecule. Binding of the histamine fragment to the end of polymer chain was confirmed by elementary analysis, nuclear magnetic resonance spectroscopy, and measuring the number-average molecular weight of the resulting polymers. It was thus possible to prepare poly(amino acids) with a pendant histamine. In addition, the lowering of the number-average degree of polymerization of the polymers prepared was observed under the condition that the initial molar ratio of NCA to histamine was larger. It was caused by the reinitiation of polymerization by the imidazole nucleus at the chain end.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.170130801
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