Synthesis, characterization, and electrochemistry of phosphine-substituted diiron butane-1,2-dithiolate complexes

Abstract

The reactions of the starting complex, [Fe₂(CO)₆{μ-SCH₂CH (CH₂CH₃)S}] (1), with the phosphine ligands tris(4-methylphenyl)phosphine, diphenyl-2-pyridylphosphine, tris(4-fluorophenyl)phosphine, 2-(diphenylphosphino)benzaldehyde, or benzyldiphenylphosphine in the presence of the decarbonylating agent Me₃NO·2H₂O yielded the corresponding phosphine-substituted diiron butane-1,2-dithiolate complexes [Fe₂(CO)₅(L){μ-SCH₂CH(CH₂CH₃)S}] (L = P(4-C₆H₄CH₃)₃, 2; Ph₂P(2-C₅H₄N), 3; P(4-C₆H₄F)₃, 4; Ph₂P(2-C₆H₄CHO), 5; Ph₂PCH₂Ph, 6) in 75%–87% yields. The complexes have been characterized by elemental analysis, IR, ¹H, and ³¹P{¹H} NMR spectroscopy, as well as by single-crystal X-ray diffraction analysis. Moreover, the electrochemistry of 2–4 was studied by cyclic voltammetry, suggesting that they can catalyze the reduction of protons to H₂ in the presence of HOAc.

Graphical Abstract

Keywords:

• Diiron butane-1,2-dithiolate
• phosphine ligand
• CO substitution
• X-ray crystallography
• electrochemistry

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by Zhejiang Provincial Natural Science Foundation of China under Grant LY19B020002, National Natural Science Foundation of China under Grant 21501124, Science & Technology Department of Sichuan Province under Grant 2018JY0235, and Education Department of Sichuan Province under Grant 18ZA0337.