Structures and magnetic properties of two heterometallic Cu(ii)–Cd(ii) polymers exhibiting antiferromagnetic ordering

Abstract

Two novel heterometallic Cu(II)-Cd(II) coordination polymers, two-dimensional (2D) [Cu2Cd(MMA)2(NTA)2(H2O)2]n (1) and one-dimensional (1D) {[CuCd(MMA)2(H2O)6]∙4H2O}n (2), were synthesized with methylmalonic acid (H2MMA) and nicotinic acid (HNTA) as mixed reactants at the...

Synthesis, X-ray structures, and magnetic properties of seven polynuclear Cu(ii) complexes containing pyrazole-3,5-dicarboxylate with various ancillary ligands

“…Upon cooling, the μ eff continuously decreases and reaches a minimum value of 0.33 μ B at 20 K for 1 and 0.34 μ B at 9 K for 4 , suggesting the predominant antiferromagnetic interaction between Cu( ii ) centers within the dimer unit coupled through the pyrazole nitrogen atoms. 52,53 Upon further cooling, a small increase of μ eff with maximum values of 0.43 μ B for 1 and 0.38 μ B for 4 at 4 K were observed and the values of μ eff drop down to 0.37 μ B for 1 and 0.32 μ B for 4 at 2 K. These behaviors suggest the presence of weak ferromagnetism at low temperature, arising from the occurrence of a canting between antiferromagnetic coupled spins. 54,55 It is well-known that spin-canting can arise from the single-ion magnetic anisotropy and antisymmetric exchange (Dzyaloshinsky–Moriya interaction).…”

Structures and luminescence properties of one co‐edge bi‐rhomboid [Zn6] based 1D stair‐stepping polymer and one quasi‐linear tetra‐nuclear [Cd4] cluster with orotic acid

“…[10][11][12][13] However, the design and synthesis of the MOCCs with excellent luminescent properties are still a great challenge because the resulting structures and performances are susceptible to many factors such as the nature of organic ligands and metal centers, temperature, pH values and solvents. [14][15][16][17][18] The d 10 metal ions of Zn(II) and Cd(II) with closed-shell electronic configuration were often used to prepare luminescent MOCCs which could display a variety of coordination numbers and avoid the attenuation or quenching of ligand-based emissions which was usually observed in the paramagnetic 3d systems. [15,19,20] In addition, a proper selection of organic ligands is also very important to build such luminescent materials.…”

“…Specifically, the research of luminescent MOCCs has attracted much attention for their promising potential in the areas of fluorescent sensors, bioprobes and hybrid organic–inorganic light‐emitting diodes (LEDs) [10–13] . However, the design and synthesis of the MOCCs with excellent luminescent properties are still a great challenge because the resulting structures and performances are susceptible to many factors such as the nature of organic ligands and metal centers, temperature, pH values and solvents [14–18] …”