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  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1197-1210 
    ISSN: 0887-624X
    Keywords: poly(ethylenimine) ; Fe(III) sequestration ; crosslinkage ; effective molarity ; 5-(bromoacetyl) salicylic acid ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three molecules of 5-(bromoacetyl) salicylate (1) complexed to Fe(III) ion were crosslinked with poly(ethylenimine) (PEI) in DMSO by alkylation of amino groups of PEI with 1, leading to the formation of Fe(Sal)3PEI, a water-soluble polymer. Several other derivatives including the immobilized form were also prepared. Examination of the values of log Kf for the PEI derivatives indicated that each Fe(III) binding site in Fe(Sal)3PEI contains three salicylate moieties. In addition, the log Kf revealed that the effective molarity (EM) of the salicylate groups contained in the Fe(III) binding site is ca. 1000M. The high EM value shows that the geometry of the coordination sphere is well conserved during the crosslinkage with PEI of 1 preassembled around Fe(III) ion. In view of the EM value and the pKa values of salicylic phenols in apo(Sal)3-PEI, the metal-free form, the three salicylate groups of each Fe(III) binding site appear to occupy proximal positions leading to effective cooperation in Fe(III) binding. Fast, strong, and selective binding of Fe(III) ion by the binding site comprising three salicylate moieties was demonstrated. In addition, rapid demetalation of the resulting complexes as well as chemical stability of the immobilized chelating agents built on PEI were achieved. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1197-1210, 1997
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 533-537 
    ISSN: 0887-624X
    Keywords: poly(ethylenimine) ; 2-carboxypyrazinyl ; self-optimization ; Ni(II) binding ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To test the concept of self-optimization of own binding site by a metal ion, host molecules for Ni(II) ion were built on poly(ethylenimine) (PEI) by using the ethylenediamine portions of PEI and 2-carboxypyrazinyl (CP) group. Two derivatives of PEI containing CP were prepared: one by random acylation of PEI with pyrazine-2,5-dicarboxylic acid mono-(2,5-dioxo-pyrrolidin-1-yl) ester (PC-DP), and the other by acylation of PEI with PC-DP in the presence of Ni(II) ion. Between these two CP derivatives of PEI, Ni(II) binding ability was more than 103 times greater for the latter. Optimization by Ni(II) ion of its own binding site built on the polymer was attributed to the preassemblage of PC-DP and PEI with Ni(II) ion and the subsequent attack at PC-DP by an amino group of PEI located in an optimal position. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 533-537, 1997.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 2935-2942 
    ISSN: 0887-624X
    Keywords: poly(ethylenimine) ; uranyl ion ; uranium extraction ; crosslinkage ; 5-(bromoacetyl)salicylic acid ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three molecules of 5-(bromoacetyl)salicylate (1) complexed to uranyl UO2+2 ion were crosslinked with branchy poly(ethylenimine) (PEI) in DMSO by alkylation of amino groups of PEI with 1, leading to the formation of UO2(Sal)U3 PEI. Upon demetalation of UO2(Sal)U3 PEI with HCl, apo(Sal)U3 PEI was obtained. Based on the pH dependence of log Kf for UO2(Sal)U3 PEI, it was concluded that each uranyl binding site in UO2(Sal)U3 PEI or apo(Sal)U3 PEI contains three salicylate moieties. In terms of the equilibrium constant for formation of the uranyl complex, apo(Sal)U3 PEI was found to be comparable to or better than the previously reported effective uranophiles. In terms of the rates for the formation of the uranyl complex, however, apo(Sal)U3 PEI was far superior to those other uranophiles. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2935-2942, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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