Explosive and pollutant TNP detection by structurally flexible SOFs: DFT-D3, TD-DFT study and in vitro recognition

Pritam Ghosh, Partha Roy, Anata Ghosh, Saibal Jana, Naresh Chandra Murmu, Subhra Kanti Mukhopadhyay, Priyabrata Banerjee

Explosive and Pollutant Nitro Aromatics (epNACs) like 2,4,6-trinitrophenol (TNP) has been detected from various surface water specimens by luminescent Schiff base Organic Frameworks (SOFs) by fluorometric method. Fluorescence intensity of the receptor SOFs have been quenched in presence of TNP due to RET and ICT, which has been confirmed through solid and solution level spectroscopic studies like FT-IR, 1H-NMR, fluorescence titration. Modern DFT (DFT-D3) calculations of the possible host guest conformers have been performed for exploration of plausible route of interaction between receptor and epNACs. The outcome of theoretical calculations is in line with experimental findings where TNP and receptor conformation mimic parallel displaced type π- π interaction. TD-DFT has been executed with both receptor and receptor ···TNP adduct, the fluorescence quenching is in line with experimental outcome. Limit of TNP detection has been found as low as 5 μM with 2.97×104 M-1 as binding constant. In real time stepping, TNP as mutagenic agent for aquatic life has been detected inside prokaryotic cells like candidia albicans in ppm level.

The MS analysis was carried out using Advion Expression® CMS ESI.