Structural and magnetic studies of tetranuclear heterometallic M/Cr (M = Co, Mn) complexes self-assembled from zerovalent cobalt or manganese, Reineckes salt and diethanolamine

Abstract

Four novel heterometallic complexes [Co 2Cr 2(NCS) 4(HDea) 2(Dea) 2]·4dmf ( 1), [Co 2Cr 2(NCS) 4(HDea) 2(Dea) 2]·4dmso ( 2), [Mn 2Cr 2(NCS) 4(HDea) 2(Dea) 2(dmf) 2]·2dmf ( 3) and [Mn 2Cr 2(NCS) 4(HDea) 2(Dea) 2(dmso) 2]·4dmso ( 4) have been prepared using zerovalent cobalt ( 1, 2) or manganese ( 3, 4), Reineckes salt, ammonium thiocyanate and a non-aqueous solution of diethanolamine (H 2Dea) in air. The single X-ray analysis reveals that all compounds have similar centrosymmetric crystal structures based on a tetranuclear {M 2Cr 2(μ 3-O) 2(μ-O) 4} (M = Co, Mn) core. Variable-temperature magnetic susceptibility measurements of 1, 2 and 4 show antiferromagnetic coupling between the magnetic centers, while 3 exhibits a ferromagnetic behavior.