Fluorescence of auramine O and its binding to poly(vinylbenzo-18-crown-6) and to polyvinylbenzoglyme in water

✍ Scribed by Wong, Kam-Han ;Kimura, Keiichi ;Smid, Johannes

• Publisher: John Wiley and Sons
• Year: 1983
• Weight: 585 KB
• Volume: 21
• Category: Article
• ISSN: 0360-6376
• DOI: 10.1002/pol.1983.170210224

✦ Synopsis

Abstract

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 × 10^4^M^−1^ (P18C6) and 1.2 × 10^4^M^−1^ (PVBG), the respective first binding constants being 317 and 63__M__^−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 BPh~4~ anions owing to formation of AuO^+^, BPh~4~^−^ ion pairs and higher aggregates.