Modulation of the magnetic dynamics in two air-stable sulfur-ligated dysprosium complexes via polymerization

Two air-stable sulfur-ligated dysprosium(III) complexes [HN(Et)3][Dy2NaL8] (1) and [DyNaL4(MeOH)x(H2O)2-x]n (2) based on 2-pyridinethiol 1-oxide (HL) were synthesized and structurally characterized. Discrete 1 and polymeric 2 share the same anionic unit of [DyL4]- with the O4S4 coordination environment, but differ in the precise geometry with triangular dodecahedron geometry in 1 and biaugmented trigonal prism geometry in 2. The subtle change leads to observable temperature-independent relaxation for 2 while a faster relaxation with invisible peak for 1 at zero dc field. Under an optimal dc field, both display the typical Raman process with a smaller pre-factor and higher exponent for 2. Ab initio calculations reveal that the predicted energy barriers are 287 cm-1 for 1 and 303 cm-1 for 2. These results demonstrate the construction and magnetic modulation of air-stable sulfur-ligated Dy-SMM architectures.