NEW COLORIMETRIC AND FLUORESCENT CHEMOSENSORS BASED ON DIPYRROMETHENE DYES

Abstract

Synthetic bis(dipyrromethene)s (H2L) is very promising compounds to create sensory systems due to a combination of spectral-luminescent and chelating properties which sensitive to structural and solvation effects. Reactions of H2L·2HBr salts with amines are accompanied by changes in the color of the solution and a clear show a transformations of H4L2+ salt spectrum in the H2L spectrum with a large (about 40 nm) difference between maxima of their intense bands which allows the use of 3,3'-bis(dipyrromethene) salts as colorimetric chemosensors of amines with sensitivity of detection upto 1·10–8 mol/l. The basis for the development of applied directions of using 3,3-bis(dipyrromethene)s as a fluorescent chemosensors of Zn2+, Cd2+ and Hg2+ ions is the bright coloristic effects, accompanying reactions of H2L with Zn(II), Cd(II) and Hg(II) salts, and significant differences in quantitative characteristics of the spectra of the complexes [M2L2] and ligands. Reactions of Zn(II), Cd(II) and Hg(II) salts with a weakly fluorescent bis(dipyrromethene) sensors are accompanied by the buildup (in 25–550 times) of fluorescence. The high sensitivity of fluorescence of d10-metal [M2L2] helikates to the properties of the environment became the basis for the development of the direction of creating fluorescent temperature sensors. The observed effect of the temperature dependence of fluorescence quantum yield of ethanol solutions of [Zn2L2] complexes is interest for the control of temperature (300–80 K). This is important in the development of cryostats or determining temperature of biomaterials cooled in them.