Electron Attachment to Triazoles and Their Complexes

A new possibility for the efficient synthesis of molecules from simple compounds similar to nature was established by the so called click chemistry. Compounds containing the triazole ring are common products of click chemistry due to the high stability of triazole. Thus, triazole derivatives became widespread in many commercially produced chemicals. On the other hand, the attachment of a free low-energy electron was found to induce bond cleavage in many molecules like for example simple constituents of DNA, with only minimal energy input. The dissociation processes in these molecules upon attachment of an electron turned out to be very selective on specific molecular bonds in the molecule and even controllable by the choice of a specific initial electron energy. These properties of electron attachment may be also employed towards triazole derivatives in order to reverse the click chemistry. In this project, we will study the dissociative attachment of free electrons to various triazole derivatives. We will use a combined experimental and computational approach to reach the project goals. Experimentally, we will generate a well-defined beam of free electrons interacting with a beam of triazole molecules. Once an electron successfully attaches to the triazole compound, the molecule becomes negatively charged. The negatively charged molecule may be unstable and dissociate while the excess electron remains at a fragment. This negative excess charge attached allows to determine the reaction products by mass spectrometry. We will study the reactions for isolated molecules in order to reveal the simple dissociation mechanisms as well as in a microenvironment, i.e. when the studied triazole derivative is surrounded by a few other molecules like water. The calculations will further provide in-depth knowledge on the experimentally observed reaction channels for isolated as well as embedded triazole derivatives. Essential aspects in this context include the energetics and dynamics of the reactions obtained in the experiment. The results of this project will shed new light on the fundamental reactions in triazole derivatives, induced by attachment of an electron. The studies at different molecular environments will also allow to reveal relevant solvation effects within the obtained chemistry. The gained basic knowledge about these technologically and biologically important molecules may also find its way into future applications. If the results indicate that the click chemistry can be indeed reversed by the electron attachment process, the action of low-energy electrons may be also exploited for the removal of triazole-based pollutants from wastewater in the future.