Syntheses, structures and magnetic properties of two new water bridged dinuclear nickel(II) complexes containing derivatives of 1,2,4-triazole and pivalate ligands

Abstract

Two new water bridged dinuclear nickel(II) complexes containing derivatives of 1,2,4-triazole and pivalate ligands, [Ni 2(μ-H 2O)(μ-admtrz) 2(piv) 4(H 2O) 2] · 13H 2O ( 1 · 13H 2O) (admtrz = 4-amino-3,5-dimethyl-1,2,4-triazole, piv = pivalate anion) and [Ni 2(μ-H 2O)(μ-adetrz) 2(piv) 4] · 3H 2O ( 2 · 3H 2O) (adetrz = 4-amino-3,5-diethyl-1,2,4-triazole) were prepared and structurally characterized. Both 1 and 2 have similar unprecedented dinuclear Ni(II) units with one water and two triazole bridges, in which each six-coordinated Ni(II) ion is further coordinated with terminal pivalate ligand and in the case of 1 also two terminal water molecules. Variable temperature magnetic susceptibility measurements for the powder samples of 1 and 2 in the range of 1.8–300 K show that weak antiferromagnetic interactions occur in 1 and 2. Theoretical fit of the magnetic data gave g = 2.198, D = −10.03 cm −1, and J = −6.88 cm −1 for 1 and g = 2.143, D = −12.31 cm −1, and J = −5.63 cm −1 for 2.