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  • 1
    Electronic Resource
    Electronic Resource
    Syntheses and some fluorescence properties of poly(2-methacrylamido-3-arylpropionic acid) (1993)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 31 (1993), S. 789-796 
    Details
    ISSN: 0887-624X
    Keywords: amphiphilic polyelectrolytes ; naphthalene ; pyrene ; fluorescence ; excimer ; energy migration ; fluorescence quenching ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Methacrylamido-3-arylpropionic acid, where aryl is 1-naphthyl (M1NpPA), 2-naphthyl (M2NpPA), or 1-pyrenyl (M1PyPA), was synthesized. Free radical polymerization gave polymers which were soluble in water at pH 〉 6. In aqueous solution, poly(M1NpPA) and poly(M2NpPA) exhibited strong excimer fluorescence as a dominant component, whereas poly(M1PvPA) showed weak monomer fluorescence as a main component. Excitation spectra and fluorescence quenching by Tl+ ions suggested that naphthyl groups in poly(M1NpPA) and poly(M2NpPA) interacted so as to form excimer sites, by which migrating excited singlets were trapped, leading to the strong excimer emission. It was suggested, however, that pyrenyl groups in poly(M1PyPA) were sterically so constrained that they could not attain the full-overlap excimer conformation but could only interact to form self-quenching sites, to which energy migration occurred, leading to weak fluorescence. © 1993 John Wiley & Sons, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1993.080310325
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  • 2
    Electronic Resource
    Electronic Resource
    Initiation of cationic polymerization of n-butyl vinyl ether by stable cation radicals of substituted phenothiazines (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 3141-3146 
    Details
    ISSN: 0887-624X
    Keywords: cationic polymerization ; phenothiazine derivatives ; cation radical ; electron transfer ; initiation mechanism ; vinyl ether ; electrochemical oxidation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3,7-Diethyl- 10-phenylphenothiazine (DEPPT), a phenothiazine derivative whose 3,7- and 10-positions are blocked, was synthesized. Potentiostatic electrolysis of DEPPT in acetonitrile (ACN) in the presence of 0.1M of LiClO4 at 0.7 V (vs. Ag/Ag/Cl) yielded the stable cation radical of DEPPT (DEPPT+·) which was characterized by cyclic voltammetry, UV-visible spectroscopy, and ESR spectrometry. Stable cation radicals of 10-phenylphenothiazine and 3,7-diethyl-10-methylphenothiazine were also prepared. The cationic polymerization of n-butyl vinyl ether was initiated by these cation radicals, including DEPPT·+. The electron transfer mechanism for the initiation step, which we proposed previously, was supported by the fact that DEPPT·+ was capable of initiating the polymerization; dimerization of DEPPT·+ by releasing protons is precluded because 3,7- and 10-positions are all blocked. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080321614
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  • 3
    Electronic Resource
    Electronic Resource
    Cationic polymerization of vinyl monomers initiated by 10-methylphenothiazine cation radicals (1994)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 1703-1710 
    Details
    ISSN: 0887-624X
    Keywords: cationic polymerization ; 10-methylphenothiazine ; cation radical ; electron transfer ; initiation mechanism ; vinyl ethers ; electrochemical oxidation ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A small quantity of 10-methylphenothiazine cation radical (MPT.+), electrochemically prepared and stocked in acetonitrile solution, initiated cationic polymerizations of n-butyl, t-butyl, and 2-methoxyethyl vinyl ethers and p-methoxystyrene, while no initiation occurred for phenyl vinyl ether, styrene, methyl methacrylate, and phenyl glycidyl ether. 1H-NMR studies of oligomers and low molecular weight compounds isolated from the reaction mixture for the polymerization of t-butyl vinyl ether in the presence of a small amount of D2O indicated that electron transfer from the monomer to MPT.+ was involved in the initiation step. 1H- and 13C-NMR and MO calculation implied that monomers with higher electron densities on the vinyl groups and with lower ionization potentials were more susceptible to the initiation of MPT.+. © 1994 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1994.080320912
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