Isostructural single-chain magnet (SCM) and single-molecule magnets (SMM) with formulas [Mn6X2(salox)(6)O-2(N-3)(8)] (X = mn(II) (1), Cd-II (2); H(2)salox = salicylaldoxime) have been synthesized and magnetically characterized. Complexes 1 and 2 possess significantly different magnetization reversal barriers of U-eff = 100.3 and 57.0 K, in spite of comparable uniaxial anisotropies (D) and ground state spin values (S). These observations are indicative of the intrinsic spin dynamics in these structurally related yet magnetically distinct SCM/SMM systems.