Disassembly Mechanisms and Energetics of Polymetallic Rings and Rotaxanes

Understanding the fundamental reactivity of poly -metallic complexes is challenging due to the complexity of their structures with many possible bond breaking and forming processes. Here, we apply ion mobility mass spectrometry coupled with density functional theory to investigate the disassembly mechanisms and energetics of a family of heterometallic rings and ro-taxanes with the general formula [NH2RR'][Cr7MF8(O2CtBu)16] with M = MnII, FeII, CoII, NiII, CuII, ZnII, CdII. Our results show that their stability can be tuned both by altering the d-metal composition in the macrocycle and by the end groups of the secondary ammonium cation [NH2RR']+. Ion mobility probes the conformational landscape of the disassembly process from intact complex to structurally distinct isobaric fragments, providing unique insights to how a given divalent metal tunes the structural dynamics.

Automated summary

This study investigates the disassembly mechanisms and energetics of a series of heterometallic rings and ro-taxanes using ion mobility mass spectrometry and density functional theory. It shows that the stability of these complexes can be tuned by altering the metal composition and end groups.