A switchable iron-based coordination polymer toward reversible acetonitrile electro-optical readout

[EN] Efficient and low cost detection of harmful volatile organic compounds (VOCs) is a major health and environmental need in industrialized societies. For this, tailor-made porous coordination polymers are emerging as promising molecular sensing materials thanks to their responsivity to a wide variety of external stimuli and could be used to complement conventional sensors. Here, a non-porous crystalline 1D Fe(ii) coordination polymer acting as a porous acetonitrile host is presented. The desorption of interstitial acetonitrile is accompanied by magneto-structural transitions easily detectable in the optical and electronic properties of the material. This structural switch and therefore its (opto)electronic readout are reversible under exposure of the crystal to acetonitrile vapor. This simple and robust iron-based coordination polymer could be ideally suited for the construction of multifunctional sensor devices for volatile acetonitrile and potentially for other organic compounds.JSC acknowledges funds from the Spanish MINECO through the National Research Project (CTQ2016-80635-P), the Ramon y Cajal Research Program (RYC-2014-16866), the Comunidad de Madrid (PEJD-2017-PRE/IND-4037) and the NANOMAGCOST (P2018/NMT-4321). EB acknowledges funds from the MSCA-IF European Commission programme (746579) and Programa de Atracción del Talento Investigador de la Comunidad de Madrid (2017-T1/IND-5562). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV-2016-0686). This research used resources of the Advanced Light Source, which is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. We acknowledge the XALOC-ALBA synchrotron source under project 2018012561. PP acknowledges financial support from the Spanish MINECO project MAT2015-67557-C2-1-P. DFT calculations were performed using resources granted by the GENCI under the CINES Grant Nos. A0020907211 and A0040907211. Additionally, the Froggy platform of the CIMENT infrastructure was employed. We thank Dr J. Perles and Dr M. Ramírez for collection and analysis of the X-ray data at the SIDI (Universidad Autonoma de Madrid)