Temperature‐induced formation of two dinuclear dysprosium complexes with different magnetic properties.

A dinuclear Dy (III) complex [Dy2(L1)2(NO3)4]·2CH3CN (1) (HL1 = 1,3‐bis{[(E)‐pyridin‐2‐ylmethylene]amino}propan‐2‐ol) was obtained via the reaction of 1,3‐diamino‐2‐propanol, 2‐pyridyaldehyde and Dy (NO3)3·6H2O at room temperature. In the structure of complex 1, two Dy (III) ions are in the N4O6 coordination environment provided by NO3− and (L1)−, and both of these ions are in the sphenocorona configuration. [Dy2(L2)2(NO3)4] (2) [HL2 = 2‐(pyridin‐2‐yl)hexahydropyrimidin‐5‐ol] was obtained using the same reaction material only when the reaction temperature was changed to 60°C. Structural analysis of complex 2 showed that the two Dy (III) ions with the same coordination configuration are in the N3O6 coordination environment provided by NO3− and (L2)− and are in the distorted spherical‐capped square antiprism. Surprisingly, HL2 with the parent of bipyridine was synthesized by the Schiff base reaction of 1,3‐diamino‐2‐propanol with 2‐pyridoxaldehyde followed by the ring‐closing reaction catalyzed by Dy (III) ions. Magnetic measurements of the Dy (III) complexes revealed no obvious frequency‐dependent behavior of complex 1. In contrast, complex 2 showed an obvious frequency dependence (Ueff = 0.49 K and τ0 = 6.62 × 10−4 s) under the condition of zero field and a weak double relaxation behavior (Ueff = 9.25 K and τ0 = 9.70 × 10−4 s) at 1500 Oe. [ABSTRACT FROM AUTHOR]