Multi-modal sensing in spin crossover compounds

Denis Gentili, Nicola Demitri, Bernhard Schäfer, Fabiola Liscio, Ilaria Bergenti, Giampiero Ruani, Mario Ruben and Massimiliano Cavallini

J. Mater. Chem. C 2015, 3, 7836-7844.


We exploited the solvatochromic spin-state switching in a spin crossover (SCO) compound based on the FeII complex and the simultaneous change of spectroscopic properties for selective multimodal sensing of methanol and ethanol. We demonstrate that sensing capabilities are due to the inclusion of methanol or ethanol molecules into the crystalline structure, which tailors simultaneously the transition temperature, colour, birefringence and vibrational modes. We exploited this capability by integrating a neutral compound, switchable at room temperature, into a micrometric TAG sensitive to the colour and birefringence. The system was characterised by optical microscopy, magnetic susceptibility, Raman spectroscopy and X-ray diffraction.