A Dysprosium Alkylidene Single Molecule Magnet

Abstract

A dysprosium alkylidene complex, supported by β-diketiminato based tridentate ligand and alkylidene ligand [C(SiMe3)PPh2Se]2‒, was synthesized and characterized. It exhibited the shortest Dy=C bond length of 2.266(3)Å to date. Magnetic measurements indicated that it was an SMM with Ueff of 305 K. Comparing its molecular magnetism and structure with the other two dysprosium complexes in the synthetic routine, the dysprosium alkylidene SMM benefited much from the Dy=C bond. Ab initio calculation revealed high crystal-field axiality despite of low symmetry. It showed strong anisotropy at ground states and first exited states. The relaxation happened through the second excited states theoretically. These researches indicated that building dysprosium complexes with one Dy-ligand multiple bond is a feasible strategy to maintain uniaxial magnetic anisotropy for Dy-SMMs.