Tellurium Containing Long Lived Emissive Fluorophore for Selective and Visual Detection of Picric Acid through Photo‐Induced Electron Transfer

A novel tellurium (Te) containing fluorophore, 1 and its nickel (2) and copper (3) containing metal organic complex (MOC) have been synthesized to exploit their structural and optical properties and to deploy these molecules as fluorescent probes for the selective and sensitive detection of picric acid (PA) over other commonly available nitro‐explosives. Furthermore, density functional theory (DFT) and single crystal X‐ray diffraction (SCXRD) techniques revealed the inclusion of “soft” Tellurium (Te) and “hard” Nitrogen (N), Oxygen (O) atoms in the molecular frameworks. Owing to the presence of electron rich “N” and “O” atoms along with “Te” in the molecular framework, 1 could efficiently and selectively sense PA with more than 80 % fluorescence quenching efficiency in organic medium and having detection limit of 4.60 μM. The selective detection of PA compared to other nitro‐explosives follows a multi‐mechanism based “turn‐off” sensing which includes photo‐induced electron transfer (PET), electrostatic (π‐π stacking and π‐anion/cation) interaction, intermolecular hydrogen bonding and inner filter effect (IFE). The test strip study also establishes the sensitivity of 1 for detection of PA. Design and development of Oxygen, Nitrogen, and Tellurium containing organic framework and its metal organic complexes for rapid and selective detection of trinitrophenol at μM concentration. Fabrication of fluorophore coated TLC sensing strips and investigation of photoinduced electron transfer mechanism.