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

Abstract

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 (N-TPT) 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 N-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 N-TPT receptors show higher binding abilities than previously reported receptors and reasonable selectivity over other volatile compounds.

Synergy of Two Intermolecular Hydrogen Bonds Promotes Highly Sensitive and Selective Room-Temperature Dimethyl Methylphosphonate Sensing: A Case of rGO-Based Gas Sensors

“…Previous publications have reported that the interaction energy between DMMP molecules and HFIP groups is 39.2 kJ/mol, which belongs to the hydrogen bond range. , In addition, our previous publication proved that hydrogen bonds were formed between PPy and DMMP molecules through FT-IR spectra characterization . Owing to the formation of two kinds of intermolecular hydrogen bonds between HFIP and DMMP, PPy and DMMP, the room-temperature DMMP sensing properties of the HFIP-PPy-rGO sensor were investigated in detail.…”

“…On the one hand, based on the hydrogen bond theory, when DMMP adsorption occurs, DMMP molecules (hydrogen bond acceptors) are more conducive to the transfer of electrons to HFIP groups (strong hydrogen bond donors), which will reduce the hole concentration in the sensing materials and increase its Fermi level to a higher level. , On the other hand, the hydrogen bond interaction-assisted adsorption mechanism leads to excellent selectivity for DMMP molecules. Previous publications have reported that the hydrogen bond energy between DMMP molecules and HFIP groups is 39.2 kJ/mol, which is significantly greater than van der Waals interaction energies (0.4–4 kJ/mol), resulting in the relatively strong adsorption capacity of sensing materials on DMMP molecules. This moderate force is not too strong to cause incomplete desorption of DMMP.…”

“…19,36 On the other hand, the hydrogen bond interaction-assisted adsorption mechanism leads to excellent selectivity for DMMP molecules. Previous publications have reported that the hydrogen bond energy between DMMP molecules and HFIP groups is 39.2 kJ/mol, 30 which is significantly greater than van der Waals interaction energies (0.4−4 kJ/mol), resulting in the relatively strong adsorption capacity of sensing materials on DMMP molecules. This moderate force is not too strong to cause incomplete desorption of DMMP.…”

Hydrophobic Amplification Enabled High‐Turnover Phosphazene Superbase Catalysis

“…Preliminary asymmetric catalysis was also implemented using chiral tertiary amine base (DHQD) 2 Pyr in combination with N-triflyl phosphoric triamide (N-TPT), recently developed by our group as a potent hydrogen-bonding donor receptor for the recognition of chemical warfare agents. [28] Using PhMe as a solvent with a catalyst loading of 10 mol % in each organic promoter, the desired product 13 was obtained with full conversion in an 82 : 18 enantiomeric ratio (e.r.). Unfortunately, this mild chiral tertiary amine system led to a low enantioselectivity (59 : 41 e.r.)…”

Fast Response-Recovery and High Selectivity Chemicapacitive Detection of a Nerve Agent Simulant Vapor

“…[17][18][19][20] Among the various receptor molecules, the development of hydrogen-bonding donors has been investigated to survey their appropriate binding modes with hydrogen-bonding acceptors in CWAs. 21,22 For example, 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP), [23][24][25] a perfluorinated carbinol, and its derivatives have been used as receptor molecules with high detection abilities for a variety of CWA simulants. [26][27][28][29][30][31][32] Inspired by recent works that use HFIP-functionalized receptor molecules, this study reports the use of POSS-based nanomaterials with multiple terminal HFIP groups, which provide efficient and high detection ability towards DMMP.…”