High-temperature magnetic blocking in a monometallic dysprosium azafullerene single-molecule magnet
Ziqi Hu, Yuanyuan Wang, Aman Ullah, Gerliz M. Gutiérrez-Finol, Amilcar Bedoya‐Pinto, Pierluigi Gargiani, Dier Shi, Shangfeng Yang, Zujin Shi, Alejandro Gaita‐Ariño, Eugenio Coronado
Abstract
Single-molecule magnets (SMMs) showing magnetic blocking near or above liquid nitrogen temperature have recently been achieved by inducing exceptionally strong and axial crystal fields (CFs) via double decker ligands. However, further enhancing the performance at higher temperatures becomes a formidable task. Here, we provide an alternative strategy to advance toward this goal by entrapping a single dysprosium(III) ion within a nitrogen-substituted carbon cage. In this structure of Dy@C 81 N, Dy III is asymmetrically coordinated by one side to a hexagonal carbon ring of the azafullerene while lacking any coordination ligand on the other side. Despite the very weak CF resulting from this very unusual low-coordination environment, this compound exhibits a high blocking temperature ( T B , defined as T (τ 100 s )) of 45 K. Its extraordinary magnetic behavior is attributed to the minimal number of vibrations that couple to its spin states and is also responsible for the unusual slow Raman relaxation mechanism observed at high temperatures.