Effects of Metal Blending in Random Bimetallic Single-Chain Magnets: Synergetic, Antagonistic, or Innocent

1D ladder and 2D bilayer coordination polymers constructed from a new T-shaped ligand: luminescence, magnetic and CO2 gas adsorption properties

1D ladder and 2D bilayer coordination polymers are constructed by using a new T-shaped ligand, in which the 2D bilayer exhibits CO₂ gas adsorption features.

An unusual homospin CoII ferrimagnetic single-chain magnet with large hysteresis

A homospin Co(ii) ferrimagnetic SCM was obtained with coexistence of 1D ferrimagnetic chains, SCM-based slow magnetic dynamics and large hysteresis.

Improved single-chain-magnet behavior in a biradical-based nitronyl nitroxide-Cu–Dy chain

The first example of nitronyl nitroxide biradical bridged 3d–4f complex exhibiting single-chain magnet behavior.

Selective and Recyclable Sensing of Aqueous Phase 2,4,6-Trinitrophenol (TNP) Based on Cd(II) Coordination Polymer with Zwitterionic Ligand

A novel coordination polymer, {[Cd4(Dccbp)4]·H2O} (1) (Dccbp = 3,5-dicarboxy-1-(3-carboxybenzyl)pyridin-1-ium) was synthesized under hydrothermal conditions by a zwitterionic organic ligand and characterized by single crystal X-ray diffraction, infrared spectrum (IR), thermogravimetric analysis (TG), powder X-ray diffraction (PXRD) and luminescence. Complex 1 with a pyridine cation basic skeleton has the potential to serve as the first case of a luminescent material based on the zwitterionic type of organic ligand for selective, sensitive, and recyclable sensing of 2,4,6-trinitrophenol in the aqueous phase.

A difunctional azido-cobalt(ii) coordination polymer exhibiting slow magnetic relaxation behaviour and high-energy characteristics with good thermostability and insensitivity

A novel one-dimensional azido-cobalt(ii) compound, [Co2(1-mbt)2(N3)4]n (1) (1-mbt = 1-((2-propyl-imidazol-1-yl)methyl)-benzo[1,2,3]triazole), was solvothermally synthesized. X-ray crystal structure analysis demonstrates that two crystallographically independent Co(ii) atoms in the asymmetrical unit of compound 1 exhibit a rectangular pyramid geometry. The 3D supermolecular network of 1 consists of well-isolated 1D metal chains in which the azido bridging ligands assume an unusual pattern of combination with the Co(ii) centre as the sign of [-EE-EO-EO-EO-]n. The various coordination modes of the azido anion are responsible for different magnetic exchanges between the adjacent Co(ii) ions. The end-to-end (EE) mode mediates the antiferromagnetic coupling, whereas the end-on (EO) manner contributes to the ferromagnetic interaction. Magneto-structural relationships are discussed with the aid of theoretical calculations which are employed to find the potential single-ion magnetic anisotropy and reproduce the observed magnetic coupling properly. Alternating current magnetic susceptibility measurements reveal that 1 features a typical behaviour of field-induced slow magnetic relaxation. Energetic characterization evidences that the resulting compound possesses satisfactory detonation properties, superior lack of sensitivity and thermostability owing to the high nitrogen content (N% = 40.10%) and a coherent intrachain configuration. The kinetic parameters of the exothermic processes for 1 are investigated by the Kissinger method and the Ozawa method. We note that 1 has potential application prospects as a new generation of environmentally friendly high-energy materials based on this nitrogen-rich and oxygen-free system. In addition, the compound is developed as a practical additive to promote the thermal decomposition of ammonium perchlorate (AP) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). The finding in this work highlights an example of effective development of advanced magneto-energetic materials.

Four 3D coordination polymers based on layers with single syn-anti carboxylate bridges: synthesis, structures, and magnetic properties

Four novel coordination polymers (CPs) based on a new 4-(3,5-dicarboxylphenyl) picolinic acid ligands (H3L), [M3(L)2(H2O)6]·4H2O (M3 = Mn3, 1; Co3, 2; Ni3, 3, Co1.01Ni1.99, 4), have been hydrothermally synthesized, and structurally and magnetically characterized. In these isomorphous CPs, octahedrally coordinated metal ions are linked by the single syn-anti carboxylate bridge (μ-COO) to give linear trinuclear motifs. The motifs are connected through the other single syn-anti carboxylate bridge (μ-COO) to give a 2D (4,4) layer, and the layers are interlinked by the L ligands into 3D frameworks. Magnetic measurement indicates that antiferromagnetic interactions between metal ions are mediated through the single syn-anti carboxylate bridges in 1 and 2, while the same carboxylate bridges in 3 transmit ferromagnetic couplings. The bimetallic CP 4 shows interesting complicated magnetic behaviors due to the competition effect of Co(ii) and Ni(ii) ions.

Crystal structure of catena-poly[aqua(μ2-1,3-bis(1H-benzo[d]imidazol-1-yl)propane-κ2 N:N′)-(μ2-5-(tert-butyl)isophthalate-κ3 O,O′:O′′)nickel(II)], C29H30N4NiO5

C29H30N4NiO5, triclinic, P1̅ (no. 2), a = 10.0887(15) Å, b = 11.2076(17) Å, c = 13.277(2) Å, α = 87.780(2)°, β = 72.138(2)°, γ = 67.129(2)°, V = 1311.0(3) Å3, Z = 2, R gt(F) = 0.0461, wR ref(F 2) = 0.1048, T = 296.15 K.

Mixed metal CoII1−xZnIIx–organic frameworks based on chains with mixed carboxylate and azide bridges: magnetic coupling and slow relaxation

A series of isomorphous three-dimensional metal–organic frameworks [Co^II_1−xZn^II_x(L)(N₃)]·H₂O (x = 0.26, 0.56 and 0.85) based on bimetallic Co^II_1−xZn^II_x (x = 0.26, 0.56 and 0.85) chains with random metal sites have been synthesized and magnetically characterized. The Co^II_1−xZn^II_x series, which intrinsically feature random anisotropic/diamagnetic sites, shows complex magnetic interactions. By gradually introducing the diamagnetic Zn^II ions into the pure anisotropic Co^II single-chain magnets system, the ferromagnetic interactions between Co^II ions are gradually diluted. Moreover, the slow magnetic relaxation behaviour of the mixed metal Co^II_1−xZn^II_x systems also changes. In this bimetallic series Co^II_1−xZn^II_x, the Co-rich materials exhibit slow relaxation processes that may arise from SCM mechanism, while the Zn^II-rich materials show significantly low slow magnetic relaxation. A general trend is that the activation energy and the blocking temperature decrease with the increase in diamagnetic Zn^II content, emphasizing the importance of anisotropy for slow relaxation of magnetization.

A series of mixed-metal systems consisting of Co^II_1−xZn^II_x chains with (μ-COO)₂(μ-EO-N₃) bridges were prepared, exhibiting interesting magnetic coupling and slow magnetic relaxation.

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.

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.

A nickel(ii)–manganese(ii)-azido layered coordination polymer showing a three-dimensional ferrimagnetic order at 35 K

The synthesis, crystal structure and magnetic properties of a two-dimensional nickel(ii)–manganese(ii)–azido system are described. It is an interesting molecular magnet because it exhibits long-range ferrimagnetic ordering at a T_c of 35 K and a hysteresis loop up to 20 K.

Slow Magnetic Relaxation in Ladder-Type and Single-Strand 2p-3d-4f Heterotrispin Chains

Ladder-type and chain 2p-3d-4f complexes based on a bridging nitronyl nitroxide radical, namely, [LnCu(hfac)₅(NIT-Ph-p-OCH₂trz)]·0.5C₆H₁₄ [Ln = Y (1a), Dy (1b)] and [LnCu(hfac)₅(NIT-Ph-p-OCH₂trz)] [Ln = Y (2a), Dy (2b); NIT-Ph-p-OCH₂trz = 2-[4-[(1H-1,2,4-triazol-1-yl)methoxy]phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; hfac = hexafluoroacetylacetonate) have been successfully achieved through a one-pot reaction of the NIT-Ph-p-OCH₂trz radical with Cu(hfac)₂ and Ln(hfac)₃·2H₂O. Complexes 1a and 1b feature a ladder-like structure, where the rails are made of Ln(III) and Cu(II) ions alternatively bridged by nitronyl nitroxide and the triazole units while the NIT-Ph-p-OCH₂trz moieties act as the rungs of the ladder. Complexes 2a and 2b consist of one-dimensional nitronyl nitroxide bridged Ln coordination polymers with dangly Cu(II) units connected to the triazole moieties. All of compounds exhibit ferromagnetic NIT-Dy and/or NIT-Cu interactions. Both Dy derivatives (1b and 2b) show frequency-dependent out-of-phase magnetic susceptibility signals in a zero field indicating slow magnetic relaxation behavior.

Five new 2D and 3D coordination polymers based on two new multifunctional pyridyl–tricarboxylate ligands: hydrothermal syntheses, structural diversity, luminescent and magnetic properties

Five new Zn(ii), Cd(ii), Co(ii) and Mn(ii) MOFs based on two novel multifunctional pyridyl–tricarboxylate ligands: structures, luminescent and magnetic properties.