Dr David C. Magri and M.Sc. graduate Kristina Farrugia of the Department of Chemistry in collaboration with Dr Damjan Makuc and Prof. Janez Plavec at the NMR Centre at the National Institute of Chemistry in Slovenia and Dr Agnieszka Podborska and Prof. Konrad Szaciłowski at AGH University of Science and Technology in Poland have jointly published a paper on colorimetric molecular sensors for anions in the European Journal of Organic Chemistry. (doi: 10.1002/ejoc.201600509)

Brilliant colour changes are observed with three of the anion sensors notably in the presence of hydroxide, fluoride and acetate anions. Less basic anions such as chloride, showed no apparent colour changes. This study provides insight into the development of more selective chemical sensors for anions. Applications of molecules able to sense for anions range from environmental analysis to medical diagnostics. 

Participation in COST Action CM1005 'Supramolecular Chemistry in Water' provided funding for detailed spectroscopic analysis by nuclear magnetic resonance (NMR) spectroscopy, a research technique that exploits the magnetic properties of certain atomic nuclei, particularly for the hydrogen and nitrogen atoms in the molecules. Colleagues from Krakow performed density functional theory (DFT) and charge distribution calculations independently confirming the mechanism of how these anion sensors work. The funding for Kristina Farrugia to read for a M.Sc. was financially supported by a Strategic Educational Pathways Scholarship (STEPS). 

Kristina N. Farrugia, Damjan Makuc, Agnieszka Podborska, Konrad Szaciłowski, Janez Plavec and David C. Magri, Colorimetric Naphthalene-based Thiosemicarbazide Anion Chemosensors with an Internal Charge (ICT) Mechanism, European Journal of Organic Chemistry, 2016, 25, 4415-4422.