Salen-Type Triple-Decker Trinuclear Dy3 Complexes Showing Slow Magnetic Relaxation Behavior

Two new Dy3 sandwich complexes, namely, [Dy3La3(CH3OH)2(NO3)3]center dot CH2Cl2 center dot CH3OH center dot 2H2O [1, H2La = N,N'-bis(salicylidene)-1,2-phenylenediamine] and [Dy3Lb3(OAc)3]center dot 3CH3OH center dot H2O [2, H2Lb = N,N'-bis(3-methoxysalicylidene)-1,2-phenylenediamine], have been synthesized from the reactions of a tetradentate salen-type ligand (H2La) with Dy(NO)3 center dot 6H2O and a hexadentate salen-type ligand (H2Lb) with Dy(OAc)3 center dot 6H2O. X-ray crystallographic analysis reveals that both 1 and 2 have a similar new triple-decker trinuclear sandwich structure. Magnetic studies indicate that 1 exhibits an antiferromagnetic interaction between the Dy3+ ions, whereas 2 exhibits a ferromagnetic interaction between spin carriers. Although both 1 and 2 display slow magnetic relaxation behavior, two relaxation processes were observed in 2, which expand on the recent reports of pure 4f-type single molecule magnets (SMMs).