<i>N</i>-Triflyl Phosphoric Triamide: A High-Performance Purely Organic Trifurcate Quartz Crystal Microbalance Sensor for Chemical Warfare Agent

Abstract

G-, V-, and A-series nerve agents are extremely toxic organophosphorus chemical warfare agents (CWAs) that incorporate P═O functional groups. Their colorless, tasteless, and odorless nature makes rapid and efficient detection challenging. Here, we report an unprecedented N-triflyl phosphoric triamide (<b>N-TPT</b>) receptor, which is a new class of triple hydrogen bonding donor molecular sensors for CWA recognition via noncovalent host-guest-type interactions. The highly robust trifurcate structures were designed based on density functional theory (DFT) computations and synthesized from <i>N</i>-triflyl phosphorimidoyl trichloride by simple stepwise processes. Quartz crystal microbalance (QCM) analysis allowed robust detection of typical CWA simulants, such as dimethyl methylphosphonate. The concentration-dependent QCM profiles were fitted with the Sips isotherm model, revealing that the thermodynamic parameters of the binding behaviors are roughly correlated with the calculated results. Developed <b>N-TPT</b> receptors show higher binding abilities than previously reported receptors and reasonable selectivity over other volatile compounds.