Novel ligand frameworks containing pyridine- and X-​type donors (X = O, S or N) for multimetallic complexes

Abstract

The structural similarity of the metal clusters in gas-processing anaerobic metalloenzymes is striking.[1] In the past decades many advances have been made in the syntheses of metal clusters. The presence of multiple metals in a single assembly, often enables metal cooperativity resulting in properties that would be otherwise elusive. However, a priori designing rigid frameworks for the controlled self-assembly of metal clusters is challenging. We recently demonstrated that the self-assembly of a wide variety of metal clusters is possible with a ligand framework contg. a 1, 3,5-triarylbenzene core with nitrogen and oxygen donors.[2] However, the presence of nitrogen, oxygen and sulfur donor sets in many gas processing enzymes inspired us to design new rigid ligand frameworks that can support multiple metals. Here we present our ongoing effort in expanding the scope in the synthesis of metal clusters by introducing a new ligand system contg. pyridine- and X-type donors (X = O, S or N). The coordination chem. of this novel ligand system with several first-row transition metals will be discussed. Moreover, the reactivity of the newly synthesized metal clusters will be explored as well. Esp. with respect to energy related problems involving gasses such as H_2, N_2, CO_2, CO and NO_x the reactivity of these multi-metallic complexes might be interesting.