A one-dimensional chain containing a mixed-valence octanuclear manganese(II,III) building unit, (NEt 4) 2n[Mn 8O 2(salox) 6(N 3) 8(MeOH) 3] n (H 2salox = salicylaldoxime), was synthesized and characterized structurally and magnetically. Each building unit contains a [Mn II 2Mn III 6O 2] 18+ structural topology. The frequency dependence of the out-of-phase component in alternating current magnetic susceptibilities and hysteresis loops for the complex indicates single-chain-magnet-like behavior. ? 2010 American Chemical Society.