Two dichloride-bridged dinuclear dysprosium(III) complexes based on salen ligands, namely, [Dy(L1 )(μ-Cl)(thf)]2 (1; H2 L1 =N,N'-bis(3,5-di-tert-butylsalicylidene)phenylenediamine) and [Dy2 (L2 )2 (μ-Cl)2 (thf)2 ]2 (2; H2 L2 =N,N'-bis(3,5-di-tert-butylsalicylidene)ethylenediamine) are reported. These two complexes have two short Dy-O(PhO) bonds that exhibit angles of ∼90° for 1 and ∼143° for 2, leading to clear slow relaxation of the magnetization for 2 and not for 1. Compound 2 has a near-identical core to the recently reported compound [Dy2 (L3 )2 (μ-Cl)2 (thf)2 ] (3; H2 L3 =N-(2-pyridylmethyl)-N,N-bis(2'-hydroxy-3',5'-di-tert-butylbenzyl)amine). The only substantial difference is the relative angle of the two O(PhO) -Dy-O(PhO) vectors, which is collinear in 2 owing to inversion symmetry and ∼68° in 3 due to a molecular C2 axis. It is shown that this subtle structural difference leads to large differences in the dipolar ground states, giving rise to open magnetic hysteresis for 3 and not for 2.
Keywords: axial linearity; dinuclear complex; dipolar interaction; dysprosium; single-molecule magnet.
© 2023 Wiley-VCH GmbH.