No abstract

Anion sensor properties of N‐alkyl‐substituted 1,4′‐diazaflavonium bromides in methanol–water were evaluated by UV–vis spectrometry. Pronounced changes were observed in the absorption spectra of all compounds for only OH−, CO32−, and CN− among F−, Cl−, Br−, I−, OH−, CO32−, NO3−, PO43−, CN−, SO42−, HSO4−, HCO3−, SCN−, NO2−, and P2O72− ions. Two new absorption bands at 385 and 685 nm accompanying the distinct color change for OH−, CO32−, and CN− ions were observed in case of all compounds. The color changes were from pink to blue for CO32− and OH− ions and from pink to purple for CN− ion. Thanks to the distinct color change, the compounds can be used as selective colorimetric anion sensors. Linear changes of absorbance of N‐heptyl‐substituted compound at 385 nm as a function of the ion concentration were used to determine CN− ion in water samples. Detection and quantification limits of the proposed method were 0.94 and 2.82 mg/L, respectively.

New phthalonitrile (L1), metal-free phthalocyanine (H2Pc) and zinc-phthalocyanine (ZnPc) substituted in peripheral positions with 2-pyridyl methyl pendant arm linked mixed donor macrocyclic ligands have been prepared in a multi-step reaction sequence. The novel compounds were characterized by a combination of elemental anlaysis, 1 H NMR, 13 C NMR, IR, UV-vis and MS spectral data. The influence of metal cations such as Cd 2+, Zn 2+, Hg 2+, Al 3+, Fe 3+ and Cu 2+ on the spectroscopic properties of dinitrile compound L1 and free phthalocyanine H2Pc was investigated by means of absorption spectrophotometry. Spectrophotometric titrations were carried out with these ligands for Cu 2+ ion. The complex composition of Cu - L1 was found 1:1 by means of spectrophotometric titration data. The spectrophotometric method showed good sensitivity for Cu 2+ with linear range of 2.6 × 10-6 to 1.3 × 10-4 M with dinitrile compound.