Heterometallic hexanuclear cluster with an S=8 spin ground state:: MnII{MnII(hfac)2}3{NiII(pao)3}2 (hfac- = hexafluoroacetylacetonate, pao- = pyridine-2-aldoximate)

The heterometallic (Mn4Ni2II)-Ni-II title compound has been synthesized and characterized by X-ray crystallography. The compound consists of a Ni-Mn-Ni linear moiety, [{Ni-(mu-NO)(3)}(2)-Mn], linked by oximate bridges and three Mn(11) hfac terminal units attached by oximate oxygens in a di-mu-oxo fashion, forming a novel heterometallic cluster. Mn{Mn(hfac)(2)}(3){Ni(pao)(3)}(2) (1). Magnetic measurements reveal the antiferromagnetic nature of the oximate pathway between Mn(11) and Ni(II) metal ions, which imposes an unusual high-spin ground state (S = 8) for 1.