ISSN:
0360-6376
Schlagwort(e):
Physics
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Binding of the cationic dye auramine O (AuO) to the polysoap-type polymers poly(vinylbenzo-18-crown-6) (P18C6) and polyvinylbenzoglyme (PVBG) in water were studied by fluorimetry and dialysis. The quantum yield of P18C6-bound AuO was found to be 0.028, the value being 0.018 for AuO bound to PVBG. The intrinsic binding constants were found to be 2.2 × 104M-1 (P18C6) and 1.2 × 104M-1 (PVBG), the respective first binding constants being 317 and 63M-1. Addition of crown-ether-complexable cations such as K+, Tl+, or Cs+ converts the neutral poly(crown ether) into a polycation, causing repulsion of the cationic dye and a strong decrease in the AuO fluorescence. AuO fluorescence was also studied in the absence of polymer in ether solvents, giving θ values of 0.011 and 0.018 in THF and dioxane. Traces of water rapidly form a nonfluorescent species. Solutions of AuO in water without polymer present exhibit very strong fluorescence on addition of BPh4 anions owing to formation of AuO+, BPh4- ion pairs and higher aggregates.
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pol.1983.170210224
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