The dinuclear mixed-valent complex [(MeC5H4)(dmpe) MnC2Mn-(dmpe)(C5H4Me)] +[(η2-MeC5H4) 3Mn]- +- (dmpe = 1,2-bis (dimethylphosphanyl)ethane) was prepared by the reaction of [Mn(MeC 5H4)2] with dmpe and Me3SnC≡ CSnMe3. The reactions of +- with K[PF6] and Na[BPh4] yielded the corresponding anion metathesis products [(MeC5H4)(dmpe)Mn-C 2Mn(dmpe)(C5H4Me)][PF6] ([PF 6]) and [(MeC5H4)(dmpe)MnC2Mn(dmpe)- (C5H4Me)][BPh4] ([BPh4]). These mixed-valent species can be reduced to the neutral form by reaction with Na/ Hg. The obtained complex [(MeC5H4)-(dmpe)MnC 2Mn(dmpe)(C5H4Me)] (1) displays a triplet/singlet spin equilibrium in solution and in the solid state, which was additionally studied by DFT calculations. The diamagnetic dicationic species [(MeC5H4)(dmpe)MnC2Mn- (dmpe)(C 5H4Me)][PF6]2 ([PF 6]2) was obtained by oxidizing the mixed-valent complex [PF6] with one equivalent of [Fe(C5H5) 2][PF6]. Both redox processes are fully reversible. The dinuclear compounds were characterized by NMR, IR, UV-visible, and Raman spectroscopy, cyclic voltammetry, and magnetic susceptibility measurements. X-ray diffraction studies were performed on , [PF6], [BPh4], and [PF6]2.
- Alkyne ligands
- Density functional calculations
- Half-sandwich complexes
- Mixed-valent compounds