24722-66-5Relevant academic research and scientific papers
Optical detection of anions using N-(4-(4-nitrophenylazo)phenyl)-N′- propyl thiourea bound silica film
Kato, Ryo,Kawai, Akinori,Hattori, Toshiaki
, p. 717 - 721 (2013/03/28)
The anion-sensing properties of N-(4-nitrophenylazo)-N′-propyl thiourea chromoionophores have been investigated as free agents in bulk solution and following immobilization on a sol-gel silica film. In addition, the effect of a variety of organic spacers on the immobilized chromoionophores was examined. The binding constants of free chromoionophores with anions were greater than those of the corresponding immobilized chromoionophores in acetonitrile solution and their binding constants revealed a trend were CH 3CO2- > H2PO4 - > Cl-. However, the use of an organic spacer with an immobilized chromoionophore can change the binding constants of anions. An octadecyl group spacer, for example, led to an increase in the difference between the binding constants of the acetate ion and other anions and also enhanced selectivity for the acetate ion.
Cyanide sensing with organic dyes: Studies in solution and on nanostructured Al2O3 surfaces
Gimeno, Nelida,Li, Xiaoe,Durrant, James R.,Vilar, Ramon
experimental part, p. 3006 - 3012 (2009/05/07)
The synthesis of two new azo phenyl thiourea compounds and their optical response to different anions is reported herein. Solution studies in methanol indicate that cyanide induces a colour change in these dyes (whereas no changes are observed in the presence of other anions, such as F-, Cl -, Br-, CH3COO-, H 2PO4-, HSO4-). Interestingly, in DMSO these dyes are responsive not only to cyanide, but also to fluoride, acetate and dihydrogen phosphate. Each of these anions induces a different colour change. In the second part of the paper, we report the attachment of one of these dyes onto nanostructured TiO2 and Al 2O3 films. The stability of these sensitised films to pH was studied and we concluded that the sensitised Al2O3 films are more robust, and hence, better than the TiO2 for anion sensing. The dye-sensitised Al2O3 films were immersed in solutions of different anions and their response studied. The films can detect cyanide down to 3 ppm in aqueous solution with relatively good selectivity over other anions.
