Heterometallic {DyIII2FeII2} grids with slow magnetic relaxation and spin crossover

The assembly of molecules simultaneously exhibiting slow magnetic relaxation and spin crossover (SCO) behaviors at the molecular level is a fascinating challenge for chemists. The synthesis strategy of combining 3d and 4f ions in a molecule is a very promising route to a dual magnetic system. With this goal in mind, a series of mixed-metal structures, namely [Dy2Fe2(H2L)(4)(OH)(6)](NO3)(4)center dot 12CH(3)OH center dot 6H(2)O (1), [Dy2Fe2(H2L)(4)(OH)(6)]Cl-4 center dot 2CH(3)OH center dot 20H(2)O (2), [Dy2Fe2(H2L)(4)(OH)(6)]Cl-4 center dot 4CH(3)OH center dot 20H(2)O (3) and [Dy2Fe2(H2L)(4)(NO3)(3)CH3O](NO3)(5)(CF3SO3)center dot 6CH(3)OH center dot H2O (4) containing a versatile Schiff-base ligand N '-((E)-pyridin-2-ylmethylene)-6-(2-((E)-pyridin-2-ylmethylene)hydrazinyl)nicotinohydrazide (H2L), have been synthesized and characterized. Alternating current (ac) susceptibility measurements reveal that complexes 1-4 exhibit a slow magnetic relaxation behavior. More importantly, complexes 2 and 3 exhibit one- and two-step SCO behaviors, respectively. To our knowledge, this is the first report on 3d-4f structures that exhibit the dual function of slow magnetic relaxation and SCO behaviors to date.

Automated summary

The study focused on the assembly of molecules exhibiting slow magnetic relaxation and spin crossover behaviors simultaneously at the molecular level. A series of mixed-metal structures containing a versatile Schiff-base ligand were synthesized and characterized, showing slow magnetic relaxation and spin crossover behaviors. Additionally, a new type of 3d-4f structure with these dual functionalities was reported for the first time, providing a novel approach for future research in the field.