title: Facile access to redox-active C2-bridged complexes with half-sandwich manganese end groups.
abstract: The dinuclear mixed-valent complex [(MeC5H4)(dmpe)MnC(2)Mn(dmpe)(C5H4Me)](+)[(eta2-MeC5H4)3Mn](-)[1](+)[2]- (dmpe=1,2-bis(dimethylphosphanyl)ethane) was prepared by the reaction of [Mn(MeC5H4)2] with dmpe and Me(3)SnC[triple chemical bond]CSnMe3. The reactions of [1](+)[2]- with K[PF6] and Na[BPh4] yielded the corresponding anion metathesis products [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)][PF6] ([1][PF6]) and [(MeC5H4)(dmpe)MnC2Mn(dmpe)(C5H4Me)][BPh4] ([1][BPh4]). These mixed-valent species can be reduced to the neutral form by reaction with Na/Hg. The obtained complex [(MeC5H4)(dmpe)MnC2Mn(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)(C5H4Me)][PF6]2 ([1][PF6]2) was obtained by oxidizing the mixed-valent complex [1][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 [1][2], [1][PF6], [1][BPh4], and [1][PF6]2.
authors.affiliation: Anorganisch-Chemisches Institut der Universität Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Sohrab
authors.initials: S
authors.lastname: Kheradmandan
authors.forename: Koushik
authors.initials: K
authors.lastname: Venkatesan
authors.forename: Olivier
authors.initials: O
authors.lastname: Blacque
authors.forename: Helmut W
authors.initials: HW
authors.lastname: Schmalle
authors.forename: Heinz
authors.initials: H
authors.lastname: Berke