Self-assembled cationic heterochiral honeycomb-layered metal complexes with the in situ generated pyrimidine-2-carboxylato bisdidentate ligand. Hydrothermal synthesis, crystal structures, magnetic properties, and theoretical study of [M2(μ-pymca)3]OH·H2O (M = FeII, CoII)

摘要: The hydrothermal reaction of 2-cyanopyrimidine and either CoCl2.6H2O or FeCl2.4H2O affords 2D isostructural coordination polymers [M2(micro-pymca)3]OH.H2O ((M = CoII (1) FeII (2) pymca pyrimidine-2-carboxylato). bisdidentate ligand (pymca) that can be considered an intermediate between bipyrimidine oxalato is generated in situ from the hydrolysis 2-cyanopyrimidine. structure 1 2 consists heterochiral (6,3) honeycomb layers, crystal water molecules, OH- anions, latter playing a template balancing charge role structure. Both compounds exhibit antiferromagnetic interactions metal ions through pyrimidine-2-carboxylate bridging ligand. Compound spin-canted antiferromagnet leading to weak ferromagnetism at Tc < 10 K with coercitive field 580 Oe, whereas compound TN 21 K. Fit variable-temperature magnetic susceptibility data empirical equation for regular S derived Monte Carlo simulations leads following parameters: J -4.57(2) cm-1 g 2.300(4). Density functional calculations have been used explain coupling 2.