Structure and Magnetic Behavior of CuIIMOFs Supported by 1,2,4-Triazolyl-Bifunctionalized Adamantane Scaffold

New Coordination Polymers of Zinc(II), Copper(II) and Cadmium(II) with 1,3-Bis(1,2,4-triazol-4-yl)adamantane

The new coordination polymers (CPs) [Zn(tr2ad)Cl2]n, {[Cu(tr2ad)Cl]Cl∙4H2O}n, [Cd2(tr2ad)Cl4]n, {[Cu(tr2ad)(NO3)](NO3)}n and {[Cd(tr2ad)(NO3)](NO3)∙H2O}n were obtained in the form of air- and moisture-stable microcrystalline powders by the solvothermal reactions of zinc(II), copper(II) and cadmium(II) chlorides or nitrates with the ligand 1,3-bis(1,2,4-triazol-4-yl)adamantane (tr2ad). Investigation of the thermal behaviour assessed the thermal stability of these CPs, with [Cd2(tr2ad)Cl4]n starting to decompose only around 365 °C. As retrieved by powder X-ray diffraction, while [Zn(tr2ad)Cl2]n features 1-D chains along which the metal centre shows a tetrahedral geometry and the spacer is exo-bidentate, the other CPs contain 2-D double-layers in which the metal ions possess an octahedral stereochemistry and the linker is exo-tetradentate. A comparative structural analysis involving known coordination compounds containing the tr2ad ligand enabled us to disclose (i) the versatility of the ligand, as far as the coordination modes are concerned; (ii) the variability in crystal structure dimensionality, ranging from 1-D to 3-D; (iii) the fact that, to the best of our knowledge, [Zn(tr2ad)Cl2]n is the first ZnII-based CP containing the tr2ad spacer.

Facile Synthesis of 3-(Azol-1-yl)-1-adamantanecarboxylic Acids-New Bifunctional Angle-Shaped Building Blocks for Coordination Polymers

For the first time, orthogonally substituted azole-carboxylate adamantane ligands were synthesized and used for preparation of coordination polymers. The angle-shaped ligands were prepared by the reaction of 1-adamantanecarboxylic acid and azoles (1H-1,2,4-triazole, 3-methyl-1H-1,2,4-triazole, 3,5-dimethyl-1H-1,2,4-triazole, 1H-tetrazole, 5-methyl-1H-tetrazole) in concentrated sulfuric acid. Variation of the solvent and substituents in azole rings allowed to prepare both 1D and 2D copper(II) and nickel(II) coordination polymers, [Cu₂(trzadc)₄(H₂O)_0.7]∙DMF∙0.3H₂O, [Cu(trzadc)₂(MeOH)]∙MeOH, [Ni(trzadc)₂(MeOH)₂] and [Cu₂(mtrzadc)₃(MeOH)]⁺NO₃^– (trzadc-3-(1,2,4-triazol-1-yl)-adamantane-1-carboxylic acid; mtrzadc-3-(3-methyl-1,2,4-triazol-1-yl)-adamantane-1-carboxylic acid) which were structurally characterized by single crystal X-ray diffraction. Complex [Cu(trzadc)₂(MeOH)]∙MeOH was shown to act as a catalyst in the Chan-Evans-Lam arylation reaction.

Three Cd(ii) coordination polymers constructed from a series of multidentate ligands derived from cyclotriphosphazene: synthesis, structures and luminescence properties

By utilizing three ligands derived from cyclotriphosphazene, three novel cadmium-based coordination polymers have been successfully synthesized and structurally characterized, which exhibit the corresponding photo-chemical properties.

Two new luminescence cadmium coordination polymers constructed by 4,4′-di(4H-1,2,4-triazol-4-yl)-1,1′-biphenyl and polycarboxylic acids: syntheses, structures, Fe3+ identifying and photo-degradable properties

Two Cd centered coordination polymers (CPs) constructed from triazole derivative and different polycarboxylic acids exhibit diverse structures and different behaviors on Fe³⁺ identifying and photo-degradation of MB.

Theoretical studies of the copper gyromagnetic factors for three novel Cu2+ coordination polymers with bi-triazole ligand

The copper electron paramagnetic resonance gyromagnetic factors are theoretically studied for three novel Cu²⁺ coordination polymers [Cu(XL)(NO₃ )₂ ]_n (1), {[Cu(XL)(4,4'-bpy)(NO₃ )₂ ]•CH₃ CN}_n (1a) and {[Cu(XL)₃ ](NO₃ )₂ •3.5H₂ O}_n (2) with bi-triazole ligand (XL) = N,N'-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide bi(1,2,4-triazole) from the high-order perturbation calculations of the g factors for a rhombically elongated octahedral 3d⁹ group. The order (1 ≤ 1a < 2) of g_z can be illustrated by the dominant second-order perturbation term roughly proportional to the square of the covalency factor N. g_x (and g_y ) relies on the combination of the contributions from N, cubic field parameter D_q , and axial elongation of the copper sites and exhibits the sequence (1 ≤ 2 < 1a). As regards the axiality (g_x  ≈ g_y ) of g factors, this is because the perpendicular rhombic contribution from the deviations of the bond lengths and bond angles for the planar ligands with respect to an ideal octahedron and that from the discrepancies between the crystal fields of the planar ligands O^2- and N^3- largely cancel each other. The present theoretical studies on the copper electron paramagnetic resonance g factors would be helpful to understand the structures and properties of some promising coordination polymers containing copper with the novel bi-triazole ligand XL.

A series of transition metal coordination polymers based on a rigid bi-functional carboxylate–triazolate tecton

By utilizing a pre-designed bi-functional ligand, five new transition-metal-based coordination polymers have been constructed and structurally characterized, along with their luminescence or magnetic properties.

A family of 12-azametallacrown-4 structural motif with heterometallic Mn(III) -Ln-Mn(III) -Ln (Ln=Dy, Er, Yb, Tb, Y) alternate arrangement and single-molecule magnet behavior

Mixed 3d-4f 12-azametallacrown-4 complexes, [Mn2 Ln2 (OH)2 (hppt)4 (OAc)2 (DMF)2 ]⋅2 DMF⋅H2 O [Ln=Dy (1), Er (2), Yb (3), Tb (4) and Y (5), H2 hppt=3-(2-hydroxyphenyl)-5-(pyrazin-2-yl)-1,2,4-triazole)], were synthesized by reactions of H2 hppt with Mn(OAc)2 ⋅4 H2 O and Ln(NO3 )3 ⋅6 H2 O. This is the first 3d-4f azametallacrown family to incorporate Ln ions into the ring sets. These isostructural complexes exhibit alternating arrangements of two Mn and two Ln ions in the rings with each pair of metal centers bound by an NN group and μ2 -O bridging. Magnetic measurements revealed dominant antiferromagnetic interactions between metal centers, and frequency-dependent out-of-phase (${\chi {^\prime}{^\prime}_{\rm{M}} }$) signals below 4 K suggest slow relaxation of magnetization.

Nickel(ii) and copper(i,ii)-based metal-organic frameworks incorporating an extended tris-pyrazolate linker

The synthesis, thermal behavior, crystal structure and adsorption properties of two novel MOFs isolated by coupling Ni(ii) and Cu(ii) to the extended tris(pyrazolate) strut 1,3,5-tris((1H-pyrazol-4-yl)phenyl)benzene are reported.