New 3D Coordination Polymers Constructed from Pillared Metal−Formate Kagomé Layers Exhibiting Spin Canting Only in the Nickel(II) Complex

Abstract

Sparked by the strategy of pillared-layer MOFs, three formate coordination polymers, {[Ni(2)(HCO(2))(3)(L)(2)](NO(3)).2H(2)O}(infinity) (1), {[Co(2)(HCO(2))(3)(L)(2)](HCO(2)).2H(2)O}(infinity) (2), and {[Cu(2)(HCO(2))(3)(L)(2)](HCO(2)).2H(2)O}(infinity) (3), have been synthesized by employing the rodlike ligand 4,4'-bis(imidazol-1-yl)biphenyl (L) as the pillar. Structural analysis indicates that the title complexes 1-3 are isostructural compounds, which possess metal-formate 2D layers perpendicularly pillared by the ligand L to afford a 3D open framework. This is an interesting example of a Kagome lattice based on the formate mediator. Moreover, the formate anion of this 2D Kagome layer exhibits various bridging modes: anti-anti, syn-anti, and 3.21 modes. Their magnetic measurements reveals that only complex 1 presents the spin canting phenomenon, while its isostructural Co(II) and Cu(II) complexes are simply paramagnets with antiferromagnetic coupling.

New 3D dicyanamide bridged coordination polymer of Ni(II): Synthesis, crystal structure, magnetic properties and antibacterial assay

“…This abrupt rise in the χT curve concomitantly with bifurcation between the ZFC and the FC curves mention above suggests the onset of long-range magnetic correlations at ca. 22 Similar behavior as been observed in Fe µ-1,3,5 bridged dicyanamides compounds, 3D Co and Ni polymers [44][45][46] or in Ni layered transition metal carboxylates and 3D MOF systems where the low temperature ferromagnetic component is usually attributed to spin-canting or ferromagnetic like interactions [47,48].…”

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

“…However, coordination polymers with rigid imidazole-containing ligands and multi-carboxylate as mixed ligands are less documented [8][9][10][11]. In our previous study, the rigid tripodal ligand 1,3,5-tris(1-imidazolyl)benzene (tib) was used to react with different benzenedicarboxylic acids for systematically investigating the impact of dicarboxylate auxiliary ligands and the counteranions on the structure of the complexes, and a series of coordination polymers have been obtained with novel structures and interesting topologies [12].…”

Hydrothermal Synthesis, Crystal Structure of Four Novel Complexes Based on Thiabendazole Ligand

“…It is worth noting that the formate anion was generated by in situ hydrolysis of DMF. [22][23][24][25][26][27] Therefore, the coordinated BTC ligands adopt monodentate mode and with {HCO 2 } − anions bridge the Zn II ions into a 1D double-chain. As shown in Figure 9, the adjacent chains are connected through weak N-H···O hydrogen bonds from N-H of TBZ together with carboxylic O atom of BTC (N6-H6···O6, N2-H2···O7).…”