Ab-Initio Molecular Dynamics Simulation of Condensed-Phase Reactivity: The Electrolysis of Amino Acids and Peptides

Abstract

Electrolysis is a potential candidate for a quick method of wastewater cleansing. However, it is necessary to know what compounds might be formed from bioorganic matter. We want to know if there are toxic intermediates and if it is possible to influence the product formation by the variation in initial conditions. In the present study, we use Car–Parrinello molecular dynamics to simulate the fastest reaction steps under such circumstances. We investigate the behavior of amino acids and peptides under anodic conditions. Such highly reactive situations lead to chemical reactions within picoseconds, and we can model the reaction mechanisms in full detail. The role of the electric current is to discharge charged species and, hence, to produce radicals from ions. This leads to ultra-fast radical reactions in a bulk environment, which can also be seen as redox reactions as the oxidation states change. In the case of amino acids, the educts can be zwitterionic, so we also observe complex acid–base chemistry. Hence, we obtain the full spectrum of condensed-phase chemistry.

Ab-Initio Molecular Dynamics Simulation of the Electrolysis of Nucleobases

“…The experimental interest in the electrochemistry of nucleobases is old [2,3], but there are also more recent publications which typically describe more complex systems [4,5]. For simulating electrolytic reactions, we use our established scheme for simulating the situation near an electrode (Figure 1, see also [1,6,7]).…”

Ab-Initio Molecular Dynamics Simulation of Condensed-Phase Reactivity: The Electrolysis of Ammonia and Ethanimine in Aquatic Carbon Dioxide Solutions

“…Theoretical studies may help to find the most important intermediates and products [13]. The reactivity of biomolecules, such as peptides and urea, that are likely to be found in municipal and agricultural wastewater were studied in previous publications [14,15]. The outcomes of these studies in the picosecond timescale were solutions containing ammonia, ethanimine, and carbon dioxide which are going to be investigated in this work.…”

“…The performance of our approach for such a system was investigated in reference [21]. In our simulations the radicals are created via simply removing nuclei and electrons from water molecules after an equilibration phase [14,15,22]. This approach models the situation immediately after the electron transfer.…”