Structural diversity and magnetic properties of six ferrocenyl monocarboxylate Mn(ii), Ni(ii) and Co(ii) complexes with 1D aqua, carboxyl or dinuclear hydroxyl bridges

Six ferrocenyl monocarboxylate Mn(ii), Ni(ii) and Co(ii) complexes with different types of magnetic coupling bridges were synthesized successfully. 1–6 display intriguing structure diversity and magnetic properties.

Three new metal coordination polymers of bifunctional imidazolate/tetrazolate bridges: the only example of a three-dimensional framework based on rare [Co4(μ3-OH)2(μ2-Cl)2]4+ mixed oxo-chloro-clusters

Three new metal coordination polymers [Ni(μ₂-L)₂(H₂O)₂]_n(1, HL = 1-tetrazole-4-imidazole-benzene), [Co(μ₂-L)₂]_n (2), and [Co₄(μ₃-OH)₂(μ₂-Cl)₂(μ₅-L)₂(μ₂-L)₂]_n·7nH₂O (3) were hydrothermally synthesized and structurally characterized. 1 displays a neutral [Ni(μ₂-L)₂(H₂O)₂]_n chain built up from the Ni²⁺ ions bridged by deprotonated L⁻ ligands, while 2 shows another rare neutral [Co(μ₂-L)₂]_n chain based on Co²⁺ ions connected by two different coordination modes of the L⁻ ligand. 3 exhibits a rare [Co₄(μ₃-OH)₂(μ₂-Cl)₂]⁴⁺ mixed oxo-chloro-cluster-based three-dimensional framework with large elliptical channels, which are filled by unprecedented chilopod [(H₂O)₇]_n chains. Both 1 and 2 show antiferromagnetic behavior, while 3 exhibits unusual spin-canting.

The interconnection of rare [Co₄(μ₃-OH)₂(μ₂-Cl)₂]⁴⁺ mixed oxo-chloro-clusters and bifunctional bridges gives a new three-dimensional framework with unusual spin-canting behavior.

Two 1D carboxylate-bridged magnets displaying solvent-dependent canted antiferromagnetic ordering

Two 1D carboxylate-bridged chain complexes can be converted irreversibly from 1 to 2 and exhibit terminal solvent-dependent canted antiferromagnetic ordering with T_C = 38 K.

Magnetic and Structural Studies of G-Phase Compound Mn6Ni16Si7

Transition metal compounds with complex crystal structures tend to demonstrate interesting magnetic coupling resulting in unusual magnetic properties. In this work, the structural and magnetic characterization of a single crystal of the Ni-Mn-Si based G-phase compound, Mn₆Ni₁₆Si₇, grown by the Czochralski method, is reported. In this structure, isolated octahedral Mn₆ clusters form an fcc lattice. As each octahedron consists of eight edge-sharing equilateral triangles, the possibility for geometric frustration exists. Magnetization and specific heat measurements showed two magnetic phase transitions at 197 and 50 K, respectively. At 100 K neutron diffraction on powder samples shows a magnetic structure with k = (001) in which only four of the six Mn spins per cluster order along ⟨100⟩ directions giving a two-dimensional magnetic structure consistent with intracluster frustration. Below the 50 K phase transition, the Mn spin-cants away from ⟨100⟩ directions, and a weak moment develops on the two remaining Mn octahedral sites.

Six novel coordination polymers based on the 5-(1H-tetrazol-5-yl)isophthalic acid ligand: structures, luminescence, and magnetic properties

Six coordination polymers containing clusters or chains have been synthesized by a combination of one tetrazolate-isophthalate ligand and N-donor ligands. Their structures, magnetic properties and luminescence properties were discussed in detail.

Four one-dimensional lanthanide–phenylacetate polymers exhibiting luminescence and magnetic cooling/spin-glass behavior

Four 1D Ln–phenylacetate polymers were synthesized hydrothermally, and displaying interesting ferromagnetic behavior, photoluminescence, significant MCE or rare spin-glass behavior.

Linking cobalt–water chains with cis-1,4-cyclohexanedicarboxylate bridges to form a 2D network exhibiting spin-canted antiferromagnetism

A 2D magnetic network consisting of water-bridged 1D Co²⁺ chains and cis-CHDA bridges displays spin-canted antiferromagnetism with spin-glass behavior.

Different magnetic responses observed in Co, Co and Co-based MOFs

Four magnetic MOFs with anisotropic Co(II) ions, {[Co5(H2O)2(μ3-OH)2(atz)2(stp)2]·1.5H2O}n (1), {[Co5(H2O)2(μ3-OH)2(trz)2(stp)2]·1.3H2O}n (2), {[Co5(H2O)6(μ3-OH)2(trz)2(stp)2]·2.5CH3OH}n (3) and {[Co3(H2O)4(Hdatrz)2(stp)2]·3H2O}n (4) (stp(3-) = 2-sulfoterephthalate, trz(-) = 1,2,4-triazolate, atz(-) = 3-amino-1,2,4-triazolate and Hdatrz = 3,5-diamino-1,2,4-triazole) were solvothermally isolated by varying the substituent groups appended on the N-heterocyclic triazole and structurally and magnetically characterized. Structural analyses indicate that the former two complexes are crystallographically isostructural, exhibiting pillared-layer frameworks with mixed triazolyl and carboxylate extended Co + Co layers supported by rigid stp(3-) connectors. Complex 3 is built from butterfly-shaped Co cluster-based layers, which are interconnected with single cobalt(ii) octahedra by ditopic stp(3-) bridges. By contrast, complex 4 consists of linear {Co3(μ-N1,N4-Hdatrz)2} subunits, which are extended by 3-connected stp(3-) linkers into a stable 3D framework. Magnetically, 1 exhibits ferromagnetic ordering below 2.7 K due to the well-organized alignment of the non-compensated resultant moment from octahedra and tetrahedral cobalt(ii) carriers, while 3 is in a non-zero paramagnetic state above 2.0 K resulting from the coexistence of intermetallic ferromagnetic and antiferromagnetic interactions. The magnetic competition between weak inter-subunit antiferromagnetic interactions and the external magnetic field makes 4 behave as a field-induced metamagnet with a critical field of 27.5 kOe. These interesting magnetostructural results suggest that the anisotropy of the moment carrier and the interlayer/intersubunit separations significantly dominate the magnetic responses in extended MOFs, providing an informative platform for the further development of interesting magnetic materials, both of academic and industrial interest.

Syntheses, structures, and magnetic properties of three new cyano-bridged heterobimetallic chains based on [Fe(Tp*)(CN)3]−

Three, new, one-dimensional (1D) heterobimetallic cyano-bridged chain complexes of squares were prepared. The simultaneous presence of magnetic and porous properties have been found in compound 1–3.

Targeted water soluble copper–tetrazolate complexes: interactions with biomolecules and catecholase like activities

Two new copper–tetrazolate complexes are synthesized and their interaction with DNA, bovine serum albumin (BSA) and catecholase like activity are explored. Interactions of the complexes with DNA are also investigated using DFT.

Spin-canting magnetization in 3D metal organic frameworks based on strip-shaped Δ-chains

Three 3D frameworks built from strip-shaped Δ-chains were prepared and magnetically characterized. The Cu(ii) compound shows spin canting, magnetic ordering and metamagnetism, while the Co(ii) and Ni(ii) compounds show canted antiferromagnetism.

Mn(ii) coordination polymers assembled from 8 or 9-connected trinuclear secondary building units: topology analysis and research of magnetic properties

Two highly-connected trinuclear Mn(ii)-cluster polymers were successfully fabricated. The FC and ZFC data of 1 show a divergence over a temperature range of 40–3.5 K. 2 features a ferrimagnetic chain with a (5/2, 10/2) spin topology.