No abstract

A covalent post-synthetic modification is applied in one of the most relevant polymers to obtain unprecedented switchable spin crossover (SCO) materials.

Detecting NO2 in an efficient manner is probably one of the major challenges to ensure a desired level of air quality. In spite of great efforts to surpass the current limitations, the commercial techniques are still strongly affected by interferences, are costly or difficult to implement in the field. Here, we investigate lanthanide metal-organic frameworks (Ln-MOF) for NO2 sensing with the aim of proposing a novel approach to surpass the present limitations. Precisely, two isostructural luminescent Ln-MOFs have been used including a recognition center (amino-group) that provides high selectivity for NO2 molecules. Energy transfer from the organic ligands to Ln is strongly dependent on the presence of NO2, resulting in an unprecedented photo-luminescent sensing scheme. Thereby, NO2 exposition triggers either a reversible enhancement or a decrease of the luminescence intensity, depending on the lanthanide (Eu or Tb). Our experimental studies combined with DFT and complete active space self-consistent field calculations, provide understanding of the nature and effects of NO2 interactions within the MOFs and the signal transduction mechanism.

A novel non-porous molecular-based acetonitrile sensor is reported. This material shows a reversible magneto-structural transition under desorption/absorption of acetonitrile involving a drastic switch in its optical and electronic properties.