Koichi Nagata

Tohoku University, Japan

Title: Synthesis and Properties of a Tetrahedral Fe Complex with Metal-Centered Chirality

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Biography

Koichi Nagata received his Ph.D. from Kyoto University (Japan) in 2016 under the guidance of supervisor Prof. Norihiro Tokitoh (Main group chemistry). During Ph.D. degree, he spent a half year as a visiting researcher at the University of Alberta, working with Prof. Eric Rivard (Main group chemistry). After obtaining his Ph.D. degree, he then undertook postdoctoral studies with Prof. Jonas C. Peters (Inorganic chemistry) at Caltech as a JSPS Overseas Research Fellow. He then joined the Shionoya group (The University of Tokyo) as a postdoctoral fellow in September of 2017. He was promoted to a project assistant professor in April of 2018, working with Prof. Mitsuhiko Shionoya (Coordination chemistry, Supramolecular chemistry). In 2020, he joined the Hashimoto group as an Assistant Professor. 

Abstract

The synthesis and characterization of molecular chirality (ex sp3-carbon center) is one of the most important areas in chemistry. Among various molecular groups, metal elements can also serve as chiral centers, so even if achiral ligands are used, it is possible to construct chiral metal complexes that have chirality only at the metal center. Such complexes are expected to be applied to enantioselective catalytic reactions and chiroptical materials. However, it is quite difficult to control the chirality of such metal-centers, because the dynamic and reversible nature of coordination bonds often lead to ligand scrambling or rapid racemization. So far, some excellent examples of relatively inert octahedral metal complexes with chirality at the metal-center only have been reported,[1] but control of the metal center of tetrahedral metal complexes is still a challenge.[2] 

This study focusses on the induction of metal center chirality in tetrahedral iron complexes. We report on the synthesis of tetrahedral metal complexes composed of only achiral ligands, where only at the metal is the chiral center, and on the control of the absolute configuration of the metal center. Specifically, a chiral tetrahedral iron complex, Fe(ABCD), was synthesized as a racemic mixture using achiral monodentate ligands (A–D). The tetrahedral monomeric structure was revealed by single-crystal X-ray diffraction analysis, along with characterization based on spectroscopic measurement and theoretical calculations.