title: Diphosphacarborane analogues of ferrocene: the synthesis of two isomeric twelve-vertex closo-[(eta5-C5H5)FeP2CB8H9] complexes.
abstract: The reaction of the Tl+ salt of the [nido-7,8,9-P2CB8H9]- anion (1-) with [CpFe(CO)2I](Cp =eta(5)-C5H5) in refluxing mesitylene for 12 h gives mixed-sandwich [1-Cp-closo-1,2,3,4-FeP2CB8H9] (2) (yield 63%). Reaction of the PPh4+ salt of the isomeric [nido-7,8,10-P2CB8H9]- anion 3- with [CpFe(CO)2I] in refluxing mesitylene gives [1-Cp-closo-1,2,3,5-FeP2CB8H9]4 (yield 56%), isomeric with 2. Compound 4 also results (yield 92%) from the sublimation of 2 under argon at ca. 350 degrees C. The constitution of all compounds is established by mass spectrometry, IR spectroscopy and multinuclear NMR spectroscopy (1H, 11B, 31P, and 13C; two-dimensional [11B-11B]-COSY, and 1H- 11B(selective)), further confirmed in the case of 4 by a single-crystal X-ray diffraction analysis.
authors.affiliation: Institute of Inorganic Chemistry of the Academy of Sciences of the Czech Republic, Rez.
authors.forename: Mario
authors.initials: M
authors.lastname: Bakardjiev
authors.forename: Josef
authors.initials: J
authors.lastname: Holub
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Carr
authors.forename: John D
authors.initials: JD
authors.lastname: Kennedy
authors.forename: Bohumil
authors.initials: B
authors.lastname: Stibr