Experimental and computational study of the inclusion complexes of β-cyclodextrin with the chemical warfare agent soman (GD) and commonly used simulants

Abstract

The inclusion complexation of the Chemical Warfare Agent soman (GD) by β-cyclodextrin is studied by both experimental and computational approaches.

Comparison of Binding Affinities of Water-Soluble Calixarenes with the Organophosphorus Nerve Agent Soman (GD) and Commonly-Used Nerve Agent Simulants

“…In agreement with the literature, this appears to be driven by the hydrophobic inclusion of aliphatic groups [ 16 , 37 ]. In contrast to reports by ourselves and others on the inclusion of OP CWAs and related compounds with cyclodextrins [ 13 , 23 ], the affinity of the complexes is in most cases fairly weak. This may be a result of non-optimized size match between the aliphatic side-chains of the guest species and the internal hydrophobic cavity, or the relative hydrophobic nature of the cyclodextrin and SCX cavities.…”

“…Quantitative 1 H-NMR titration experiments were again conducted and association constants determined by EQNMR analysis as K 11 = 75 and <10 M −1 for the SCX4 and SCX6 hosts, respectively. It should be noted that, unlike with β-cyclodextrin [ 23 ], there was no observation of chiral discrimination as a result of complex formation. This is expected, given that the SCX hosts are achiral and chiral recognition using calixarenes is usually achieved through either the incorporation of chiral functionality or of asymmetry [ 28 , 29 ].…”

“…In a recent study, we reported comparative agent–simulant data in the hydrophobically-driven inclusion complexes of β-CD with GD, common trialkylphosphates and dialkyl methylphosphonates, using both experimental and computational DFT approaches; considerable differences in complex affinity between GD and simulants were observed. Furthermore, the use of computational methods allowed for deconvolution of association constants to calculate diastereoisomer-specific complex affinities of the four diastereoisomers of GD [P(+)C(+), P(+)C(−), P(−)C(−), P(−)C(+)] [ 23 ]. A further theoretical study has considered the formation of inclusion complexes of the CWA GB and a range of simulants by α-cyclodextrin, alongside spectroscopic calculations for the V-series agents VX and VG and the G-series agents GA, GB, GD and GF [ 24 ].…”

Identification of organophosphorus simulants for the development of next-generation detection technologies

“…It is therefore vital to consider the appropriate properties of any simulant chosen to aid in the development of novel OP CWA detection, decontamination, or remediation methodologies. [21][22][23][24] Recently, work undertaken by Snurr and Mendonca, has shown that density functional theory (DFT) can be used to study the mechanism of OP hydrolysis, which has resulted in the development of a quantitative structure activity relationship (QSAR) model that enables the identification of appropriate OP CWA simulants for decontamination purposes. 25 However, when considering supramolecular technologies, the moiety target is often selective coordination of the polar PvO functionality.…”

“…Compounds 11-15 are commercially available species commonly used to simulate OP CWAs. The structures of simulants 5-10 and 16-26 were designed to fulfil the following criteria: charge neutrality; not readily ionised under experimental conditions; containing a single electrophilic site (S or P); and containing a single HBA centre (either a PvO (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), or OvSvO (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)).…”