Solid-State Versus Solution Investigation Of A Luminescent Chiral Binol-Derived Bisphosphate Single-Molecule Magnet

The 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).