Different delocalized ranges in mixed valence cyanido-metal-bridged Fe-Ru-Fe complexes controlled by terminal ligand substitution modification

Chen Zeng; Qing-Dou Xu; Xiao-Lin Liu; Sheng-Min Hu; Xin-Tao Wu; Tian-Lu Sheng

doi:10.1039/d3dt02208k

Different delocalized ranges in mixed valence cyanido-metal-bridged Fe-Ru-Fe complexes controlled by terminal ligand substitution modification

Dalton Trans. 2023 Nov 21;52(45):16858-16869. doi: 10.1039/d3dt02208k.

Authors

Chen Zeng^{1

2}, Qing-Dou Xu¹, Xiao-Lin Liu^{1

2}, Sheng-Min Hu¹, Xin-Tao Wu¹, Tian-Lu Sheng¹

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P.R. China. tsheng@fjirsm.ac.cn.
² School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P.R. China.

PMID: 37910432
DOI: 10.1039/d3dt02208k

Abstract

In order to investigate the properties of metal to metal charge transfer (MMCT) influenced by the relative energy level between the bridging unit and the terminal unit, two groups of heterotrimetallic cyanido-metal-bridged complexes, trans-[Cp(dppe)Fe-CN-Ru(MeOpy)₄-NC-Fe(dppe)Cp][X]_n (1[X]n; n = 2, 3, or 4; X = PF₆ or BF₄) (Cp = cyclopentadiene, dppe = 1,2-bis(diphenylphosphino)ethane, MeOpy = 4-methoxypyridine) and [Cp*(dppe)Fe-CN-Ru(MeOpy)₄-NC-Fe(dppe)Cp*] [X]_n (2[X]n; Cp* = 1,2,3,4,5-pentamethylcyclopentadiene; n = 2, 3, or 4; X = PF₆ or BF₄) were synthesized and fully characterized. The crystallography data suggest different oxidation sites in the ground state for one-electron oxidation products 13+ and 23+, and the electrochemical and Mössbauer spectra suggest that in the one-electron oxidation compounds 13+, the charge is delocalized all along the trimetal backbone Fe-Ru-Fe, while in 23+, the charge is rather delocalized between the two metal parts Fe-Ru. Further oxidation of N3+ gives N4+ (N = 1 or 2), during which a spin transfer towards the terminal units is observed in both series.