Simulation of Reaction Pathways for On-Surface Polymerization

Abstract

On-surface synthesis is an alternative approach for the manufacture of polymers, currently under development, which enables creating materials not accessible by conventional wet chemistry. Molecules are deposited on a metal surface acting as support and catalyst for reactions, interlinking the monomers into polymers, enabling the formation of many fascinating materials. A major challenge with this approach is that the on-surface reactions are difficult to predict. Therefore, the quest for finding new materials with on-surface synthesis has been, to a large extent, based on trial-and-error experimentation. Last years’ computer simulations, in terms of electronic structure theory and transition state theory, have played an important role in elucidating the reaction mechanisms of reactions relevant to on-surface polymerization, bringing us closer to the appreciation needed to anticipate how molecules react on surface. Here, the author highlights some of the theoretical work that has been performed to gain knowledge about reactions on surfaces aided by computer simulations, and particularly focuses on the on-surface Ullmann coupling, the surface-chemistry of terminal alkynes and an electrocyclic ring-closure reaction. The discussion will be centered both around the prevailing theoretical understanding as well as what knowledge we are currently lacking, and what we may expect from computer simulations during forthcoming years.