A 5d-3d bimetallic compound was prepared by self-assembling [W(CN)(8)](3-) and the Mn-III Schiff bases. This neutral complex consists of cyanide-linked anionic chains and isolated Mn-III Schiff base cations. We demonstrate that two types of relaxation processes are involved in the system; the low-T dynamics may come from magnetic domain dynamics and the high-T relaxation stems from the anionic chain, revealing single-chain magnet character.