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 CuAuCN does not react with vapour phase dimethyl sulphide (DMS) or diethyl sulphide (DES) despite the independent synthesis of emissive [CuAuCN](DMS) and [CuAuCN](DES) from their constituent components in solution. However, the doped CuAuCN 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 CuAuCN with Cu(i) generates an active sensor material. This response can be thermally cycled with little to no loss in functionality. [CuAuCN](DMS), [CuAuCN](DMS), and [CuAuCN](DES) were structurally characterized as 3-D network structures supported by aurophilic interactions.
ZnPt(CN)4 was shown to be an effective material for ammonia sensing, and can be synthesized using either solution or mechanochemical methods. A combination of luminescence and Raman spectroscopy revealed that multiple species are involved in the reaction between ammonia and ZnPt(CN)4. The crystal structure of one of these species, Zn(NH3)2Zn(NH3)3(Pt(CN)4)2, was elucidated. Detection of ammonia vapor down to 50 ppm in air was accomplished by monitoring the luminescence spectrum. The reaction between ZnPt(CN)4 and ammonia vapor is reversible, and can be cycled multiple times by either flowing air over the material or heating. ZnPt(CN)4 also has a relatively high thermal stability, decomposing only when heated above 420 °C.
Targeting the low‐oxygen (hypoxic) environments found in many tumours by using redox‐active metal complexes is a strategy that can enhance efficacy and reduce the side effects of chemotherapies. We have developed a series of CuII complexes with tridentate pyridine aminophenolate‐based ligands for preferential activation in the reduction window provided by hypoxic tissues. Furthermore, ligand functionalization with a pendant CF3 group provides a 19F spectroscopic handle for magnetic‐resonance studies of redox processes at the metal centre and behaviour in cellular environments. The phenol group in the ligand backbone was substituted at the para position with H, Cl, and NO2 to modulate the reduction potential of the CuII centre, giving a range of values below the window expected for hypoxic tissues. The NO2‐substituted complex, which has the highest reduction potential, showed enhanced cytotoxic selectivity towards HeLa cells grown under hypoxic conditions. Cell death occurs by apoptosis, as determined by analysis of the cell morphology. A combination of 19F NMR and ICP‐OES indicates localization of the NO2 complex in HeLa cell nuclei and increased cellular accumulation under hypoxia. This correlates with DNA nuclease activity being the likely origin of cytotoxic activity, as demonstrated by cleavage of DNA plasmids in the presence of the CuII nitro complex and a reducing agent. Selective detection of the paramagnetic CuII complexes and their diamagnetic ligands by 19F MRI suggests hypoxia‐targeting theranostic applications by redox activation.
Ammonia is a common coolant, including in ice skating rinks, but is a hazardous material. ZnPt(CN)4 was shown to exhibit a blue/green luminescence‐based sensory response when exposed to ammonia vapor, as shown in the cover image. The reaction between ZnPt(CN)4 and ammonia is detectable down to 50 ppm of ammonia, and is fully reversible. The reaction involves several species depending on the exposure time and concentration of ammonia, which were characterized using vibrational and luminescence spectroscopy. One of these species, Zn(NH3)2Zn(NH3)3(Pt(CN)4)2 has been structurally characterized as a 1D coordination polymer. More information can be found in the Full Paper by D. B. Leznoff et al. on page 9017.
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