Mixed Cu(i)/Au(i) coordination polymers as reversible turn-on vapoluminescent sensors for volatile thioethers

Abstract

Vapour-phase thioethers play an important role in a wide number of fields, including plant biology, chemical weapon disposal, and brewing but few sensor materials are known. The emissive coordination polymer Cu_1/2Au_1/2CN does not react with vapour phase dimethyl sulphide (DMS) or diethyl sulphide (DES) despite the independent synthesis of emissive [Cu_1/2Au_1/2CN]₂(DMS) and [Cu_1/2Au_1/2CN]₂(DES) from their constituent components in solution. However, the doped Cu_2/3Au_1/3CN rapidly reacts in the solid state with both of these vapour phase thioethers reversibly, with a change in emission from 380/560 nm to 460 nm (DMS) or 420 nm (DES), illustrating that doping the inactive parent Cu_1/2Au_1/2CN with Cu(I) generates an active sensor material. This response can be thermally cycled with little to no loss in functionality. [Cu_1/2Au_1/2CN]₂(DMS), [Cu_2/3Au_1/3CN]₂(DMS), and [Cu_2/3Au_1/3CN]₂(DES) were structurally characterized as 3-D network structures supported by aurophilic interactions.