Molecular Rearrangement of an Aza-Scorpiand Macrocycle Induced by pH. A Computational Study

Rearrangements and their control are a hot topic in supramolecular chemistry due to the possibilities that these phenomena open in the design of synthetic receptors and molecular machines. Macrocycle aza-scorpiands constitute an interesting system that can reorganize their spatial structure depending on pH variations or the presence of metal cations. In our case, the conformations change varies between the so called ‘open’ and ‘closed’, the last being found at lower pH. In this study, the relative stabilities of these conformations were predicted computationally by the Density Functional Theory approximation and the reorganization from closed to open was simulated by using the Monte Carlo Multiple Minimum method.