Identification of novel triazolylquinoxaline-based metal complexes supported by experimental and virtual screenings†

The formation of novel complexes from so far non-investigated ligands and different metal centers is important for the development of new functional materials such as (photo)catalysts or biologically active compounds. Still, promising strategies to quickly and systematically investigate the complexation behavior of selected ligands are rare. We developed an NMR-based screening approach to monitor changes within reaction mixtures containing metals and ligands on a small scale via a simple but reliable protocol. Based on the obtained data, we could draw conclusions on the formation of 2-(1′,2′,3′-triazol-1′yl)quinoxaline-based transition metal complexes. The NMR screening results obtained were confirmed by the repetition of selected experiments on a large scale, and wherever possible, the type of complex obtained was evaluated by crystal structure elucidation. We could show the versatile complexation of the selected ligands with copper, gold, and silver in a bridging, chelating, or monodentate manner. The calculated theoretical properties supported the experimental results and enabled initial in silico predictions of similar compounds before conducting the complexation experiments and structural analyses.