Ferromagnetically coupled single-chain magnets exhibiting a magnetic hysteresis of 0.42 Tesla in cyano-bridged FeIII2MII (M = Ni, Fe) coordination polymers

The synthesis, single-crystal structures and magnetic properties of two new double-zigzag-chain cyano-bridged heterobimetallic {[MII(Py-NOH)2][FeIII(Tp*)(CN)3]2}·H2O ([FeIII2MII]) (Py-NOH = 4-pyridinealdoxime, Tp* = tris(3,5-dimethylpyrazol-1-yl)borohydride, M = Ni (1), Fe (2)) compounds are reported. The crystal structures of both compounds were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are isostructural, with the crystal structure comprising neutral double-zigzag (4,2-ribbon-like) bimetallic chains. The FeIII ion is coordinated by three cyanide carbon atoms and three nitrogen atoms of Tp* anions. However, the MII ion is surrounded by four cyanide nitrogen atoms and two nitrogen atoms from two Py-NOH ligands. The crystal structures and magnetic studies demonstrate that both complexes behave as single-chain magnetics (SCMs) with intrachain ferromagnetic coupling. Furthermore, [FeIII2NiII] exhibits an excellent coercive field of 0.42 T at 1.8 K, among cyano-bridged 3d transition-metal-based SCMs reported thus far. Preliminary theoretical calculations provide a deep understanding of the magnetic properties of [FeIII2NiII].

Guest-Induced Switching of a Molecule-Based Magnet in a 3d-4f Heterometallic Cluster-Based Chain Structure

With the motivation of controlling a magnetic switch by external stimuli, we report here an infinite chain structure formed from the secondary building units of Cu₃Tb₂ clusters through the linkage of nitrate ions. It behaves as a molecule-based magnet with the highest energy barrier among isolated Tb/Cu-based single-molecule magnets and single-chain magnets, which is close to a dimer of a Cu₃Tb₂ cluster unit from a magnetic point as revealed by its correlation length of 2.23 Cu₃Tb₂ units. This kind of molecule-based magnet in a chain structure is rare. The removal of its guest ethanol molecules leads to the complete disappearance of slow magnetic relaxation behavior. Interestingly, the capture and removal of guest ethanol molecules are reversible, mediating a rare ON/OFF switching of a 3d-4f heterometallic molecule-based magnet, which was interpreted by the theoretical calculations based on the structural difference upon desolvation.

Magnetic relaxation in a Co(ii) chain complex: synthesis, structure, and DFT computational coupling constant

We report a homospin non-solvated Co^II chain compound constructed by two similar tridentate ligands and chloride ions, which displays slow magnetic relaxation below 5 K.

A cobalt(ii) chain based on pymca generated in situ from the hydrolysis of 2-cyanopyrimidine: spin canting and magnetic relaxation

A one-dimensional (1D) coordination polymer, [{Co2(pymca)2·(H2O)4}SO4·2H2O] n (1) (pymca = 2-carboxypyrimidine), was solvothermally synthesized via the reaction of 2-cyanopyrimidine and Co(SCN)2. A bidentate pymca ligand was formed in situ by the hydrolysis of 2-cyanopyrimidine. Furthermore, in this study, the magnetic properties of complex 1 were investigated in detail. The results indicated that complex 1 showed a single-chain magnet (SCM) behavior below ca. 3 K. The energy barrier (Δτ 1/k B) and preexponential factor (τ 0) of SCM were 31.2 K and 5.4 × 10-9 s, respectively.

Single-chain magnets assembled in cobalt(ii) metal–organic frameworks

This feature article discusses the advantages, progress and prospects of constructing single-chain magnets in metal–organic frameworks.

Random mixed-metal Co1−xNix single-chain magnets with simultaneous azide, carboxylate and tetrazolate bridges

A series of MOFs based on random ferromagnetic Co_1−xNi_x chains with simultaneous azide, carboxylate and tetrazolate bridges show metamagnetism and slow magnetic relaxation with complicated composition dependence and synergistic effects on single-chain slow dynamics.

Two 3d–4f double helical chains including [Dy2M2]n (M = NiII and CoII) cores exhibiting slow magnetic relaxation

Two new heterometallic complexes with one-dimensional ladder-like double-helical chain structures were prepared. They both exhibit interesting magnetic properties.

Spin canting, metamagnetism, and single-chain magnetic behaviour in a cyano-bridged homospin iron(II) compound

Spin canting, antiferromagnetic ordering, metamagnetism and single-chain magnetism were verified in a cyano-bridged Fe(II) compound synthesized from the pentagonal bipyramidal Fe(II) starting material in the presence of excessive BF4(-) anions.

Structural and magnetic tuning from a field-induced single-ion magnet to a single-chain magnet by anions

By choosing different anions, a mononuclear field-induced single-ion magnet and a one-dimensional single-chain magnet were selectively prepared and characterized.