A triangular Dy3 single-molecule toroic with high inversion energy barrier: magnetic properties and multiple-step assembly mechanism

Abstract

In the present study, we designed and synthesized a triangular-shaped Dy₃ single-molecule toroic with an energy barrier of 130 K. The above Dy₃ cluster has the highest energy barrier among the reported triangular-shaped Ln₃ single-molecule toroics. For the first time, Electrospray Ionization Mass Spectrometry (ESI-MS) was used to study the gradual splitting of a trigonal lanthanide cluster, which provided a reference for studying the assembly mechanism. The time-dependent ESI-MS technique was used to track the changes of reaction species, and a multi-step assembly mechanism for Dy₃ clusters was proposed in combination with the fracture mechanism: [Dy(L)]⁺ → [Dy₂(L)₃]⁺ → [Dy₃(L)₄]⁺ → [Dy₃(L)₅]⁺/[Dy₃(L)₅]′⁺.