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 this study, the relative stabilities of these conformations were predicted computationally by semi-empirical and density functional theory approximations, and the reorganization from closed to open conformations was simulated by using the Monte Carlo multiple minimum methodFinancial support by the Spanish Ministerio de Economía y Competitividad (Projects CONSOLIDER INGENIO CSD-2010-00065 and CTQ2013-48917-C3-1-P), Generalitat Valenciana (Project PROMETEOII2015-002) is gratefully acknowledged. Emili Besalú acknowledges the Generalitat de Catalunya (Departament d'Innovació, Universitats i Empresa) for the financial support given to the QTMEM (Química Teòrica i Modelatge i Enginyeria Molecular) research group of the University of Girona (code 2014-SGR-1202