Syntheses, crystal structures, and magnetic properties of two isostructural complexes (trenH(4))(2)[CoX4]X-6 (X = Cl, Br)

摘要

Two novel complexes (trenH(4))(2)[CoCl4]Cl-6 and (trenH(4))(2)[CoBr4]Br-6 (tren = tris(2-aminoethyl)amine) were isolated in the form of single crystals from the aqueous systems CoX2-tren-HX (X = Cl, Br). The chemical composition of formed complexes was corroborated by chemical analysis and IR spectroscopy. The crystal structures of isostructural compounds are ionic and are built up of tetrahedral anions [CoX4](2-), additional halogenido anions X-, and tetraprotonated (trenH(4))(4+) organic cations. The organic cations and complex anions are also connected beside ionic forces by hydrogen bonding interactions of the N-H center dot center dot center dot X type. The temperature variable magnetic studies (2-300 K) confirm the paramagnetic behavior of both complexes with zero-field splitting parameter D governing the magnetic behavior below 30 K. The fitting procedures yielded for D/hc values of +10.5 and +13.8 cm(-1) for the chlorido and the bromido complex, respectively.