Selective Detection of Water in Methanol by 2,4-Dihydroxy Benzaldehyde Schiff Base and Its Applications: An Experimental and Theoretically Approach.

Selective and sensitivity qualitative detection of tiny amounts of water in organic solvents remains a hot research area due to its tremendous application in pharmaceutical, medical, chemical laboratory, industrial etc. Hence, this work devoted, design a simple and cost-effective Schiff base namely, 4-((thiazol-2-ylimino)methyl)benzene-1,3-diol (L) by simple condensation of 1: 1 molar ration of 2-aminothizaole and 2,4-dihydroxy benzaldehyde. The probe (L) was employed for selective detection of trace water in methanol (CH3OH) solvents. The dark yellowish color solution of L changed to light yellow in color upon addition of water, which is visible through naked eye. Upon addition of water to the methanolic solution of L, enhancement of fluorescence was observed with a detection limit (LOD) of 0.1634 wt %. The enhancement of fluorescence emission is due to the formation of aggregation induced emission fluorescence enhancement (AIEE). Further, formation of AIEE was established through dynamic light scattering (DLS), scanning electron microscope (SEM) and quantum mechanical (DFT and TDDFT) analysis. Finally, probe was used to detect qualitatively tiny amounts of moisture in various raw food adducts (wheat, sugar salt, honey) and various building materials (sand, cement, limestone, and fly ash).