Superatomic Stabilization of Dinuclear Platinum(III) through Iodide-Bridged Five-Center Ten-Electron Bonding

Masanori Wakizaka; Hisaaki Tanaka; Shinya Takaishi; Masahiro Yamashita

doi:10.1021/acs.inorgchem.4c04178

Superatomic Stabilization of Dinuclear Platinum(III) through Iodide-Bridged Five-Center Ten-Electron Bonding

Inorg Chem. 2024 Dec 19. doi: 10.1021/acs.inorgchem.4c04178. Online ahead of print.

Authors

Masanori Wakizaka¹, Hisaaki Tanaka¹, Shinya Takaishi², Masahiro Yamashita^{2

3}

Affiliations

¹ Department of Applied Chemistry and Bioscience, Faculty of Science and Technology, Chitose Institute of Science and Technology, 758-65 Bibi, Chitose 066-8655, Japan.
² Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Aoba-Ku, Sendai 980-8578, Japan.
³ School of Chemical Science and Engineering, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China.

PMID: 39700064
DOI: 10.1021/acs.inorgchem.4c04178

Abstract

One of the goals in synthetic chemistry is to obtain compounds featuring unusual valence states that are stable under ambient conditions. At present, stabilizing unusual Pt(III) states is considered difficult, except through direct Pt-Pt bonding such as that in platinum-blues or organometallization using bulky ligands. Pt(III) stabilization is also very difficult in halogen-bridged metal complex chains (MX-Chains). Herein, the iodide-bridged Pt(III) dimer compound [Pt₂(en)₄I₃]I₃ (en = ethylenediamine), which is prepared by the iodine oxidation of [Pt^II(en)₂]I₂, has been successfully synthesized and characterized. This compound is stable and is obtained as diamond-shaped single crystals with a lustrous emerald-green color under reflected light and a red color under transmitted light. The Pt(III) state is stabilized by the five-center ten-electron (5c-10e) bonding in the I-Pt-I-Pt-I core, in addition to the very strong antiferromagnetic state. The stabilization mechanism of Pt(III) through a 5c-10e bonding is considered a superatom complex; thus, this work provides new insight for stabilizing the unusual Pt(III) state.