The preservation of sarin and

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Chemical Warfare Agent Simulant Studies

Background:

• O,O'-diisopropyl fluorophosphate (DFP) is a simulant for phosphonofluoridate G-series chemical warfare agents.
• Investigating host-guest interactions is crucial for understanding molecular encapsulation and reactivity.
• Coordination cages offer unique environments for encapsulating guest molecules.

Purpose of the Study:

• To investigate the host-guest chemistry of DFP with octanuclear cubic coordination cages.
• To explore the potential for cage-catalyzed hydrolysis of DFP at near-neutral pH.
• To assess the impact of coordination cages on the stability of organophosphorus compounds.

Main Methods:

• Synthesis and characterization of octanuclear cubic coordination cages (HPEG and HW).
• Host-guest interaction studies with DFP in aqueous buffer solutions (pH 8.7).
• Crystallographic analysis to determine the binding mode of DFP within a related host cage.
• Hydrolysis rate studies of sarin (GB) in the presence of the HPEG cage.

Main Results:

• Two coordination cages, HPEG and HW, increased the lifetime of DFP in aqueous solution, inhibiting hydrolysis.
• Crystallography revealed DFP binds to cage surface windows, directing the P-F bond inward and protecting it.
• The HPEG cage significantly reduced the hydrolysis rate of the chemical warfare agent sarin (GB).

Conclusions:

• Octanuclear coordination cages can inhibit the hydrolysis of organophosphorus compounds like DFP and sarin.
• The binding mechanism involves encapsulation at cage surface windows, protecting the reactive P-F bond.
• This protective effect has potential applications in forensic sample preservation and analysis of chemical warfare agents.