COが配位した生体模倣型[Mo₃S₄M] (M = Fe, Co, Ni)クラスター錯体の理論計算

概要

令和４年度

京都大学化学研究所 スーパーコンピュータシステム 利用報告書

CO が配位した生体模倣型[Mo3S4M] (M = Fe, Co, Ni)クラスター錯体の理論計算
CO-Bound Biomimetic [Mo3S4M] (M = Fe, Co, Ni) Clusters: A Computational Study
University of Colombo

W. M. C. Sameera

研究成果概要
Transition metal clusters can be used as catalysts to perform chemically or biologically relevant
reactions.1,2 Relationships between the electronic structure and reactivity can be established by
employing density functional theory (DFT). We have developed [Mo3S4M]-type clusters (M = Fe,
Co, Ni), consisting bulky cyclopentadienyl ligands (CpXL, C5Me4SiEt3). CO can be coordinated
to [Mo3S4M] cubes. According to experimental data, [CpXL3Mo3S4M(CO)]+ (M = Co, Ni) is stable,
while [CpXL3Mo3S4Fe(CO)]+ complex revealed unexpected instability. Their M-CO interactions
were analyzed by DFT calculations.
An energy decomposition analysis (EDA) together with the natural orbitals for chemical
valence (NOCV) was performed to rationalize the M-CO interactions. The interaction energy
between M and CO follows the
order of Fe-CO (-101.1 kcal/mol)
> Co-CO (-81.5 kcal/mol) > NiCO (-77.3 kcal/mol). In all three
cases,

orbital

interactions

become dominant compared to
electrostatic, dispersion, and solvent interactions. According to EDA-NOCV, π back-donation
from Co to π*(CO) is stronger than 𝜎𝜎 CO to M(d) 𝜎𝜎 donation for all three systems. These findings

give quantitative insights to develop bio-mimetic catalysts for the direct conversion of CO into
hydrocarbons.

発表論文（謝辞あり）
(1) Y. Ohki, K. Munakata, R. Hara, M. Kachi, K. Uchida, M. Tada, R. E. Cramer, W. M. C.
Sameera, T. Takayama, Y. Sakai, S. Kuriyama, Y. Nishibayashi, K. Tanifuji, “Nitrogen reduction
by the Fe sites of synthetic [Mo3S4Fe] cubes”, Nature, 607, 86-90 (2022).
(2) W. M. C. Sameera, Y. Takeda, Y. Ohki, “Transition Metal Catalyzed Cross-coupling and
Nitrogen Reduction Reactions: Lessons from Computational Studies”, Adv. Organomet. Chem.,
78, 35-78 (2022).
(3) K. Tanifuji, Y. Sakai, Y. Matsuoka, M. Tada, W. M. C. Sameera, Y. Ohki, “CO Binding onto
Heterometals of [Mo3S4M] (M = Fe, Co, Ni) Cubes”, Bull. Chem. Soc. Jpn., 95, 1190-1195 (2022). ...