A novel two-dimensional Ni(II) fumarato complex: Solvothermal synthesis, crystal structure and magnetic properties

[Ni(fum)(phen)], prepared by the solvothermal method, exhibits a 2D crystal structure with bridging fumarato ligands. The presence of {Ni}2 pairs in the structure, forming antiferromagnetic S = 1 dimers with magnetic anisotropy D/kB = −6 K comparable to intra-dimer exchange coupling J, is reflected by magnetic measurements down to 2 K.