Half-Sandwich Iridium Complexes Bearing a Diprotic Glyoxime Ligand: Structural Diversity Induced by Reversible Deprotonation

Taishin Takamura; Takuya Harada; Tatsuro Furuta; Takao Ikariya; Shigeki Kuwata

doi:10.1002/asia.201901276

Half-Sandwich Iridium Complexes Bearing a Diprotic Glyoxime Ligand: Structural Diversity Induced by Reversible Deprotonation

Chem Asian J. 2020 Jan 2;15(1):72-78. doi: 10.1002/asia.201901276. Epub 2019 Oct 22.

Authors

Taishin Takamura¹, Takuya Harada¹, Tatsuro Furuta¹, Takao Ikariya¹, Shigeki Kuwata¹

Affiliation

¹ Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1 E4-1 O-okayama, Meguro-ku, Tokyo, 152-8552, Japan.

PMID: 31577045
DOI: 10.1002/asia.201901276

Abstract

Synthesis and deprotonation reactions of half-sandwich iridium complexes bearing a vicinal dioxime ligand were studied. Treatment of [{Cp*IrCl(μ-Cl)}₂ ] (Cp*=η⁵ -C₅ Me₅ ) with dimethylglyoxime (LH₂ ) at an Ir:LH₂ ratio of 1:1 afforded the cationic dioxime iridium complex [Cp*IrCl(LH₂ )]Cl (1). The chlorido complex 1 undergoes stepwise and reversible deprotonation with potassium carbonate to give the oxime-oximato complex [Cp*IrCl(LH)] (2) and the anionic dioximato(2-) complex K[Cp*IrCl(L)] (3) sequentially. Meanwhile, twofold deprotonation of the sulfato complex [Cp*Ir(SO₄ )(LH₂ )] (4) resulted in the formation of the oximato-bridged dinuclear complex [{Cp*Ir(μ-L)}₂ ] (5). X-ray analyses disclosed their supramolecular structures with one-dimensional infinite chain (1 and 2), hexagonal open channels (3), and a tetrameric rhomboid (4) featuring multiple intermolecular hydrogen bonds and electrostatic interactions.

Keywords: Crystal engineering; Hydrogen bonds; Iridium; N ligands; O ligands.

Abstract

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