Molecular Thioamide ↔ Iminothiolate Switches for Sulfur Mustards

SNS platinum­(II) pincer complexes reversibly bind and release the surrogate half sulfur mustard, 2-chloroethyl ethyl sulfide (CEES). The switch-like behavior of the pincers is attributed to a reversible transformation between the thioamide and iminothiolate forms of the pincer skeleton under slightly acidic and basic conditions, respectively. An amide-based palladium­(II) pincer complex also binds CEES, as confirmed crystallographically and by NMR.