Theme 1 colloquium by prof. Bruno Martínez Haya (Universidad Pablo de Olavide, Seville, Spain): 'Wandering protons and dynamic molecular structures' (Lecture)

The elucidation of supramolecular structures and their rationalization in terms of specific non-covalent interactions constitutes one main aim of Physical Chemistry. Scientists in the field benefit from a broad range of experimental and computational developments, leading to unprecedented capabilities to gain information at the atomic level. The close inspection of molecular arrangements reveals remarkable cases in which molecular structure is actually not well defined. We investigate these situations within the framework of relatively simple proton-bonded systems, showing that molecular domains involved in proton-bonding interactions often feature dynamic changes in their chemical identity.
The main focus of the talk will be on loose-proton coordination in molecular rings with multiple binding sites, where facile proton diffusion may recurrently induce reversible chemical changes in guest molecules. Our research is based on the combination of laser vibrational spectroscopy of isolated protonated complexes (at FELIX) with molecular modelling based on quantum chemical and molecular dynamics computations.