Structural and Experimental Oxidation State Characterization of Molecular Cobalt Complexes

Cost-effective and sustainable first-row transition metal complexes are highly sought-after in synthesis and catalysis. We have been studying the activation and functionalization of white phosphorus (P4) using Fe, Co, and Ni complexes with a recent breakthrough being the synthesis of functionalized bis(acyl)phosphines from P4 facilitated by low-valent cobalt complexes. To achieve a detailed understanding of the underlying mechanisms, it is crucial to determine the structures of the metal complexes involved. Furthermore, determining the oxidation states of the Co atoms, especially for low or even negative oxidation states, presents a significant challenge. This proposal has two primary objectives: First, the high-precision structural elucidation of various Co complexes using X-ray diffraction (XRD). Second, the experimental determination of oxidation states of the Co atoms using K-edge X-ray absorption spectroscopy (XAS).