Filling a Gap: Electrochemical Property Comparison of the Completed Compound Series [Mo₂(DArF)_n(O₂C-Fc)_4–n] (DArF = N,N′-Diarylformamidinate; O₂C-Fc = Ferrocenecarboxylate)

Abstract

The reaction of cis-[Mo2(O2C-Fc)2(NCCH3)4][BF4]2 (cis-1) with two electronically different N,N'-diarylformamidinate (DArF) ligands (DArF = N,N'-bis(p-trifluoromethylphenyl)formamidinate (DTfmpF), N,N'-bis(p-anisyl)formamidinate (DAniF)) results in the isolation of the tris- and monosubstituted complexes [Mo2(DTfmpF)3(O2C-Fc)] (2a) and [Mo2(DAniF)(O2C-Fc)3] (2b). These complexes complete the series of [Mo2(DArF)n(O2C-Fc)4-n] (n = 4-0) type compounds, thus allowing for a comprehensive study. On the basis of the oxidation potential E1/2([Mo2](4+)/[Mo2](5+)) of all Mo2 complexes, ligand basicity is found to decrease in the order DAniF(-) > DTfmpF(-) > Fc-CO2(-) ≫ CH3CN. In addition, no direct electronic interaction between the trans-positioned Fc units in complex 2b is detected, which is attributed to the full overlap of all Fc oxidation processes. Furthermore, the low-energy absorption bands of compounds 2a,b are located at different positions in their respective UV-vis spectra.

Ferrocene-Bearing Homoleptic and Heteroleptic Paddlewheel-Type Dirhodium Complexes

“…Paddlewheel-type dinuclear (M 2 ) complexes, which have metal-metal bonds or interactions, have long been known as versatile building blocks that can rationally coordinate Inorganics 2024, 12, 41 2 of 14 organic ligands or metalloligands at the equatorial positions of the M 2 cores [18]. Fcabearing paddlewheel-type M 2 complexes have been investigated for several M 2 cores, such as Cu, Zn, Mo, Ru, and Rh [19][20][21][22][23][24][25][26][27][28]. For example, Churchill reported the crystal structure of [Cu 2 (fca) 4 (THF) 2 ], in which four fca and two THF ligands are coordinated to the equatorial and axial positions, respectively, of a Cu 2 core, and four ferrocene units adopt both eclipsed and staggered conformations in a 2:2 ratio [19].…”