title: Electronic communication in oligometallic complexes with ferrocene-based tris(1-pyrazolyl)borate ligands.
abstract: Ferrocene-based tris(1-pyrazolyl)borate ligands 1R-Li and 1R-Tl have been synthesized and used to generate a variety of heterotrinuclear transition metal complexes, 3R-M [R = H, SiMe(3), cyclohexyl, (cyclohexyl)methyl, phenyl; M(II) = Mn, Fe, Co, Ni, Cu, Zn]. The poor solubility of 3H-M is greatly enhanced by the introduction of large organic substituents into the 4-positions of all pyrazolyl rings. The unsubstituted ligand 1H-Li and the trinuclear complex 3Cym-Cu [Cym = (cyclohexyl)methyl] have been investigated by X-ray crystallography. 1H-Li, which represents the first example of a structurally characterized lithium tris(1-pyrazolyl)borate, forms centrosymmetric dimers in the solid state. A severe Jahn-Teller distortion was observed for the (Bpz(3))(2)Cu fragment in 3Cym-Cu. Compared to the parent compounds [(HBpz(3))(2)M], the presence of uncharged ferrocenyl substituents in 3R-M tends to shift the M(2+)/M(3+) redox potential to significantly more cathodic values. The opposite is true if the ferrocenyl fragments are in their cationic state, which results in an anodic shift of the M(2+)/M(3+) transition. Most interestingly, the two ferrocenyl fragments in 3R-Cu appear to be electronically communicating.
authors.affiliation: Institut für Anorganische Chemie and Institut für Organische Chemie, J. W. Goethe-Universität Frankfurt, Marie-Curie-Str. 11, D-60439 Frankfurt (Main), Germany.
authors.forename: S
authors.initials: S
authors.lastname: Guo
authors.forename: F
authors.initials: F
authors.lastname: Peters
authors.forename: F F
authors.initials: FF
authors.lastname: de Biani
authors.forename: J W
authors.initials: JW
authors.lastname: Bats
authors.forename: E
authors.initials: E
authors.lastname: Herdtweck
authors.forename: P
authors.initials: P
authors.lastname: Zanello
authors.forename: M
authors.initials: M
authors.lastname: Wagner