Jahn-Teller Switching of a Redox-Active Nickel(III) Center in a Homoleptic Thiolato Metalloligand Environment

Masahiro Kouno; Naoto Kuwamura; Nobuto Yoshinari; Tatsuhiro Kojima; Malcolm A Halcrow; Kohei Yamagami; Akira Sekiyama; Takumi Konno

doi:10.1021/acs.inorgchem.3c00554

Jahn-Teller Switching of a Redox-Active Nickel(III) Center in a Homoleptic Thiolato Metalloligand Environment

Inorg Chem. 2023 Jun 19;62(24):9463-9470. doi: 10.1021/acs.inorgchem.3c00554. Epub 2023 Jun 6.

Authors

Masahiro Kouno^{1

2}, Naoto Kuwamura^{1

3}, Nobuto Yoshinari¹, Tatsuhiro Kojima¹, Malcolm A Halcrow⁴, Kohei Yamagami^{5

6}, Akira Sekiyama⁷, Takumi Konno^{1

8}

Affiliations

¹ Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
² Hyogo Prefectural Institute of Technology, Kobe, Hyogo 654-0037, Japan.
³ Center for Promotion of Higher Education, Kogakuin University, Hachioji, Tokyo 192-0015, Japan.
⁴ School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
⁵ Japan Synchrotron Radiation Research Institute (JASRI), Sayo-gun, Hyogo 679-5198, Japan.
⁶ Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
⁷ Division of Materials Physics, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
⁸ Department of Chemistry, Faculty of Science, National Taiwan Normal University, Taipei 11677, Taiwan.

PMID: 37279336
DOI: 10.1021/acs.inorgchem.3c00554

Abstract

Treatment of nickel(II) nitrate with the iridium(III) metalloligand fac-[Ir(apt)₃] (apt = 3-aminopropanethiolate) gave the trinuclear complex [Ni{Ir(apt)₃}₂](NO₃)₃ ([1_Ir](NO₃)₃), in which the nickel center has a formal oxidation state of +III. Chemical or electrochemical oxidation and reduction of [1_Ir](NO₃)₃ generated the corresponding trinuclear complexes [Ni{Ir(apt)₃}₂](NO₃)₄ ([1_Ir](NO₃)₄) and [Ni{Ir(apt)₃}₂](NO₃)₂ ([1_Ir](NO₃)₂) with one-electron oxidated and reduced states, respectively. Single-crystal X-ray crystallography revealed that the nickel center in [1_Ir](NO₃)₃ is situated in a highly distorted octahedron due to Jahn-Teller effect, while the nickel center in each of [1_Ir](NO₃)₄ and [1_Ir](NO₃)₂ adopts a normal octahedral geometry. Crystals of [1_Ir](NO₃)₃·2H₂O are dehydrated on heating while retaining their single-crystallinity. The dehydration induces temperature-dependent dynamic disorder of the Jahn-Teller distortion at the nickel(III) center, which is largely quenched upon rehydration of the crystal.