Structural diversity of silver (I) azine complexes – Effect of substituents and counter anions

A pyrene based novel di-Schiff base colorimetric and turn-on fluorescent-chemosensor for selective and sensitive detection of Hg2+ ion: Biological, logic gate and real sample applications

Following a simple synthetic process, a new pyrene derivative with a benzildihydrazone moiety has been synthesised and used for selective detection of Hg2+ across four distinct channels (colorimetric, absorption, emission, and bio-imaging). When Hg2+ was present, the chemosensor L exhibited a noticeable increase in fluorescence, changing colour from yellow to colourless, while other metal ions only caused slight variations in fluorescence intensity as well as colour. The fluorescent-based assay's sensitivity for Hg2+ is 1.04 × 10-6 M and colorimetric detection limit is 7.83 × 10-6 M, which are significantly lower than the threshold specified in the World Health Organization's (WHO) drinking water guidelines. The 1:1 stoichiometric complexation between L and Hg2+ is demonstrated by the Job plot, and the ESI-MS spectra data. L has practical applications in real sample analysis, molecular logic gate and biology. Confocal fluorescence microscopy imaging in MCF 7 and human lymphocyte cells (HLCs) showed that L could be used as an effective fluorescent probe for detecting Hg2+ in living cells. Moreover L may be employed as anticancer drug without causing any harmful consequences at the given concentrations and incubation duration. L has also real sample and logic gate application.

Crystal structures and spectral properties of two polyoxometalate-based inorganic-organic compounds from silver-azine building blocks with bis-bidentate and tridentate ligands

Two polyoxometalate-based inorganic-organic hybrid compounds constructed from silver(I)-L species and saturated Keggin type polyoxoanion, [Ag2L2(1)]2(SiMo12O40)·1.5DMF·0.5CH3OH⋅H2O 1 and [{Ag4L2(2)(DMF)5}(SiMo12O40)] 2 (L(1) = phenyl 2-pyridyl ketone azine, L(2) = 3-phenyltriazolo[1,5-a]pyridine), have been synthesized and structurally characterized by IR, UV, elemental analysis, XRPD and complete single crystal structure analyses, where the ligands L(1) and L(2) are bis-bidentate and tridentate azines synthesized with the same materials under different conditions. The structure of 1 exhibits a dinuclear double-helicate with [SiMo12O40](4)(-) anions as counter ions, where all of the Ag centers coordinate to bis-bidentate chelating ligands. Compound 2 displays a two-dimensional sheet formed by the Ag-organic infinite chains and the [SiMo12O40](4)(-) alternately arranged in a "rail-like" fashion. The luminescent properties of 1 and 2 in the solid state were investigated.