Poly(ionic liquid)s with controlled architectures and their use in the making of ionogels with high conductivity and tunable rheological properties

International audienceWe describe the preparation as well as the electrochemical and mechanical properties of a series of novel well-defined poly(ionic liquids) (PILs) featuring a finely tuned cross-linking ratio. We generate a variety of such PILs with various cationic moieties and cross-linking ratios starting from a common polymeric platform. Mixing those polymers with an appropriate ionic-liquid leads to ionogel electrolytes exhibiting good ionic conductivities (up to 1.2 mS cm−1 at 298 K), high electrochemical stability (up to 6 V) and a yield-stress fluid mechanical behavior, which enables their use as solid electrolytes. We demonstrate that depending on the cationic moieties, this ability to be solid at rest and reversibly fluid when sheared is obtained by two different mechanisms

Solid-state: Versus solution investigation of a luminescent chiral BINOL-derived bisphosphate single-molecule magnet

International audienceThe enantiopure coordination polymer [Dy(hfac)3((S/R)-L)]n ([(S/R)-1]n) involving a BINOL-derived bisphosphate ligand (S/R)-L is reported. Paramagnetic NMR and computational investigations demonstrated the formation of mononuclear species [(S/R)-1] in CH2Cl2 solution and its optimized structure was determined. The experimental electronic circular dichroism signals of (S/R)-L were strongly enhanced after metal coordination [(S/R)-1]. Both polymeric and mononuclear structures displayed field-induced Single-Molecule Magnet (SMM) behaviour with similar multi-relaxation processes due to the retention of crystal-field splitting determined by CASSCF calculations, despite the strong structural transformation between the two media. The HOMO ? LUMO transition of the (S)-L ligand induced the classical Dy(iii) emission at 77 K that was correlated with the magnetic properties. [(S)-1]n is described as one-dimensional assembly of chiral luminescent Single-Ion Magnets (SIMs)