Spin Transitions in Fe(II) Metallogrids Modulated by Substituents, Counteranions, and Solvents

Abstract

Two bis(tridentate) Schiff base ligands H2L(x) were used to construct three 2×2 grid-type tetranuclear Fe(II) complexes 1-3 to obtain polynuclear spin-crossover materials. Magnetic susceptibility measurements show that the spin states of the complexes are related to the substituents of H2L(x), and that spin transition occurs only in complexes 1 and 2, which are derived from a bulky ligand, whereas complex 3 is diamagnetic. The transition temperatures of complexes 1 and 2 are close to room temperature and are dependent on counteranions. The spin transition of complex 1 can be reversibly tuned by the dehydration and hydration process.

Structure Switching and Modulation of the Magnetic Properties in Diarylethene‐Bridged Metallosupramolecular Compounds by Controlled Coordination‐Driven Self‐Assembly

“…At 100 and 293 K, the average Fe II −N bond length was 1.957 and 1.965 Å, respectively (Table S5). This value is within the range that is expected for an LS Fe II −N bond length . Results from the thermogravimetric (TG) analysis indicated that Fe III 2 Fe II 2 (o‐ L syn ) 2 is stable at 450 K but loses lattice solvents (Figure S11).…”

Detection of dopamine on a mercapto-terminated hexanuclear Fe(III) cluster modified gold electrode

“…In the last two decades, the development of advanced functional poly-nuclear iron-oxo clusters has gained increased interest in magnetic materials, bioinorganic, and biological chemistry [1][2][3][4][5]. A serial of poly-iron clusters containing bridging oxygen centers (such as Fe2, Fe3, Fe6) have been synthesized and their magnetic properties have been investigated [1,3].…”

Programmable spin-state switching in a mixed-valence spin-crossover iron grid

“…Approaches to the generation of multi-bistable systems include the crystallization of mononuclear SCO complexes in asymmetric packing environments 21 , the co-crystallization of different bistable molecules 22 and the linkage of two or more bistable building blocks in a molecular system, in which the stabilization of an intermediate state depends on the degree to which neighbouring chromophores are electronically coupled 23 . Cooperative SCO behaviour, mediated by the steric and electronic stress applied to neighbouring metal centres by multidentate or bridging ligands, has been reported in dinuclear complexes 23 , tetranuclear squares 24,25 and grid-like complexes [26][27][28] . Indeed, the study of grid-type clusters is of particular interest, as their tunable electronic states 29,30 have seen them proposed as quantum cellular automata; molecular binary logic devices that function through coulombic interactions between metal centres on neighbouring cells 31 .…”