투고논문

Synthesis of α-oximinoketones, Precursor of CO₂ Reduction Macrocyclic Coenzyme F430 Model Complexes

Gilhoon Kim and Hoshik Won*

Department of Chemical and Molecular Engineering, Hanyang University, Ansan, 15588, Republic of Korea

Abstract Ni(II) containing coenzyme F430 catalyzes the reduction of CO₂ in methanogen. Macrocyclic Ni(II) complexes with N,O shiff bases have been received a great attention since metal ions play an important role in the catalysis of reduction. The reducing power of metal complexes are supposed to be dependent on oxidoreduction state of metal ion and structural properties of macrocyclic ring moiety that can enhance electrochemical properties in catalytic process. Six different α-oximinoketone compounds, precursor of macrocyclic ligands used in CO₂ reduction coenzyme F430 model complexes, were synthesized with yields over 90% and characterized by NMR. The molecular geometries of a-oximinoketone analogues were fully optimized at Beck’s-three-parameter hybrid (B3LYP) method in density functional theory (DFT) method with 6-31+G* basis set using the ab initio program. In order to understand molecular planarity and substitutional effects that may enhance reducing power of metal ion are studied by computing the structure-dependent ¹³C-NMR chemical shift and comparing with experimental results.