A linear trinuclear cobalt(II) complex with 4-(2-pyridine)-1,2,4-triazole: synthesis, structure and characterization

Abstract

The linear trinuclear cobalt(II) complex [Co3(pytrz)6(H2O)6](NO3)6 (1) with pytrz = 4-(2-pyridine)-1,2,4-triazole has been prepared and characterized. It crystallizes in the rhombohedral R-3 space group with Z = 3, a = 13.955(2), b = 13.955(2), c = 28.942(9) Å, γ = 120°, V = 4881.2(18) Å3. The structure of 1 comprises the cation [Co3(pytrz)6(H2O)6]6+, in which linear trinuclear Co(II) units are bridged by six L ligands and have six aqua molecules as terminal ligands. The six free nitrates link the terminal aqua ligands through N–H ··· O hydrogen bonds with C3 symmetry. 1 was characterized by FT-IR, electronic spectra and magnetic measurements. The variable-temperature magnetic measurements reveal weak anti-ferromagnetic interactions in 1.