Self-Assembly, Rearrangement and Disassembly of {Cr6} Horseshoe Oligomers

Molecular assemblies are commonly found in biological systems; designing and reporting on synthetic mimics of these is a challenge for modern chemistry. Here, we apply ion mobility mass spectrometry (IM-MS), density functional theory calculations and mass-selective electrospray ion beam deposition followed by low temperature scanning tunnelling microscopy (STM) to decipher the self-assembly, rearrangement and disassembly processes of {Cr6}n horseshoe oligomers (n = 1 - 5). Activated tandem IM-MS reveals the oligomer disassembly in detail, highlighting the stability of the dimer unit. When n = 2 and 3 oligomers are deposited on surfaces, we observe the rearrangement of dimers and trimers to dimers of dimers, as characterised by low temperature STM. In its entirety, the experimental and computational data provide a convincing framework for the analysis of supramolecular assembly processes in non-crystalline phases that could be used in future design strategies