Quantum molecular study of sulfur mustard

Abstract

The sulfur mustard, HD, a chemical warfare agent, has been studied by ab initio quantum molecular computations (~~/ 6 -3 1 6 * and 6-316) on its various forms (neutral, ethylene sulfonium, and free carbonium ions). The geometries of these molecules have been completely optimized and the minimal energy conformations determined with their associated charge distributions. We discuss these results on electrostatic properties with respect to the mechanism of DNA alkylation by HD and compare them with our previous study of the nitrogen mustard mechlorethamine.

Conformational Analysis of Sulfur Mustard from Molecular Mechanics, Semiempirical, and ab Initio Methods

“…It is interesting that a previous ab initio study4 at the HF/ 6-31G level reports the energetics of an HD structure similar to 4 except that the a2 and a3 torsional angles were apparently constrained to 60°, rather than allowed to relax. The resulting structure was found to be 3.76 kcal/mol higher in energy than the all-anti structure.…”

Ab initio modeling of the interaction between guanine?cytosine base pair and mustard alkylating agents

“…The mechanism of the alkylation of guanine N7 by sulfur mustard in episulfonium form was modeled using the supermolecule represented in Figure 5, in which the (G + C) base pair geometry is the one obtained above and the HD' episulfonium has the geometry and conformation determinated previously at the HF/6-31G level [19,21].…”

Ab initio GB study of chemical intermediates in solution; Ethylenesulfonium ion in hydrolysis of 2-chloroethyl methyl sulfide

“…‫ם‬ D E ‫ס‬ ‫3.11מ‬ kcal/mol (10) This process is a simple proton transfer reaction and proceeds with a small activation energy. In other words, 3 is difficult to form from 4 by the reverse reaction, and thus the reaction of 1 with a nucleo- phile such as H 2 O leads to a stable ring-opened compound that will not easily be converted to the cyclic sulfonium ion.…”

“…Recent theoretical studies [9][10][11][12][13][14] have examined the structure and reactivity of sulfur mustard and CEMS. Politzer and Habibollahzadeh [11] calculated the bonding properties of sulfur mustard in solution using ab initio SCRF theory with Onsager's reaction field model.…”