Increasing the Effective Energy Barrier Promoted by the Change of a Counteranion in a Zn-Dy-Zn Smm: Slow Relaxation Via the Second Excited State

The trinuclear complex [ZnCl(μ-L)Dy(μ-L)ClZn]PF6 exhibits a single-molecule magnetic behaviour under zero field with a relatively large effective energy barrier of 186 cm-1. Ab initio calculations reveal that the relaxation of the magnetization is symmetry-driven (the DyIII ion possesses a C2 symmetry) and occurs via the second excited state. © The Royal Society of Chemistry 2015.