51028-33-2Relevant academic research and scientific papers
Isatin N-phenylsemicarbazone: Effect of substituents and concentration on anion sensing selectivity and sensitivity
Cig, Marek,Jakusov, Klaudia,Donovalov, Jana,Sz?cs, Vojtech,Gplovsk, Anton
, p. 54072 - 54079 (2015/01/09)
The effect of substituent and concentration on anion sensing selectivity and sensitivity of nine new easily synthesized isatin N-phenylsemicarbazone E-isomer sensors IIIa-XIa was investigated. The substantial difference between the association constants for IIIa-XIa interaction with strongly and weakly basic anions allows detection of F- or CH3COO- anions even at high weakly basic anion excess. Substitution in position 5- of the isatin ring and para-substitution on the phenyl ring in the phenylsemicarbazide chain influence sensor:anion complex stoichiometry and thus also sensor sensitivity. Detection limits of 3-4 × 10-7 mol dm-3 for F- and CH3COO- anions by sensors IVa and Va bearing electron-withdrawing substituents are among the lowest published detection limits for these anions in organic solvents. The high selectivity and sensitivity of sensor VIa allows confident F- detection at tolerated fluoride drinking-water level. The solution dilution leads to a dramatic change in sensor selectivity. Consequently, one E-isomer can be used to sense both strongly and weakly basic anions. On the other side, higher sensor solution concentrations increase the F- and CH3COO- anion detection range, similar to the additional Z-isomer utilization. This journal is
