Structure and magnetic properties of a trinuclear nickel(II) complex with benzenetricarboxylate bridge

Novel trinuclear Ni(II) complex [Ni3(pmdien)3(btc)(H2O)3](ClO4)3 · 4H2O, 1 where pmdien = N,N,N′,N′,N″-pentamethyldiethylenetriamine, H3btc = 1,3,5-benzenetricarboxylic (trimesic) acid, has been prepared and structurally characterized. Three nickel atoms are bridged by btc trianion and their coordination sphere is completed by three N atoms of pmdien and O atom of the water molecule. The three nickel(II) magnetic centers are equivalent and their coordination spheres are completed to deformed octahedrons. Magnetic susceptibility was measured over the temperature range 1.8–300 K and zJ′ = −0.19 cm−1, D = 3.79 cm−1, g = 2.18 parameters were calculated.

Transition metal complexes containing bridges connecting central atoms have received considerable interest not only as bioinorganic model complexes and catalysts, but they are also studied for their interesting structural, magnetic and spectral properties.In this paper, we reported new trinuclear nickel(II) complex [Ni3(pmdien)3(H2O)3(btc)](ClO4)3 · 4H2O, where pmdien = N,N,N′,N′,N″-pentamethyldiethylenetriamine, H3btc = 1,3,5-benzenetricarboxylic (trimesic) acid. The complex magnetic data indicated that nickel(II) magnetic centers in the trimer are isolated as a result of 1,3,5-benzentricarboxylic bulky ion causes sterical hindrance preventing magnetic interaction between inside trimers. The obtained results evidences an occurrence zero-field splitting effect and antiferromagnetic exchange interaction between nickel(II) trimeric units.Figure optionsDownload as PowerPoint slide