title: Rhenium(V) oxo complexes with acetylacetone derived Schiff bases: structure and catalytic epoxidation.
abstract: Substitution reactions of rhenium(V) oxo precursors [ReOCl3(PPh3)2] or [NBu4][ReOCl4] with the bidentate acetylacetone-derived ketoamine ligands APOH = 4-anilino-3-penten-2-one, DPOH = 4-[2,6-dimethylanilino]-3-penten-2-one, and MTPOH = 4-[2-(methylthio)anilino]-3-penten-2-one gave the complexes [ReO(APO)Cl2(PPh3)] (1), [ReO(DPO)Cl2(PPh3)] (2), and [NBu4][ReOLCl3] (3, L = APO; 4, L = DPO; 5, L = MTPO), respectively. All complexes exhibit only one ketoamino chelate, independent of the amount of ligand added to the rhenium precursors. The complexes were characterized by 1H and 13C NMR spectroscopy. X-ray crystal structures of the complexes 1, 2, 4, and 5, including that of MTPOH, were determined, revealing the trans position of the two oxygen atoms and the trans-Cl,Cl conformation in 1 and 2, in contrast to most other rhenium complexes of this type where the cis-Cl,Cl conformation is observed. Coordination of the potentially tridentate ligand MTPOH in 5 is bidentate with a dangling thioether substituent. Compound 2 shows catalytic activity in the oxidation of cis-cyclooctene with tert-butylhydroperoxide.
authors.affiliation: Institut für Chemie, Karl-Franzens-Universität, Schubertstrasse 1, A-8010 Graz, Austria.
authors.forename: Anna
authors.initials: A
authors.lastname: Sachse
authors.forename: Nadia C
authors.initials: NC
authors.lastname: Mösch-Zanetti
authors.forename: Ganna
authors.initials: G
authors.lastname: Lyashenko
authors.forename: J Wolfram
authors.initials: JW
authors.lastname: Wielandt
authors.forename: Kerstin
authors.initials: K
authors.lastname: Most
authors.forename: Jörg
authors.initials: J
authors.lastname: Magull
authors.forename: Fabio
authors.initials: F
authors.lastname: Dall'Antonia
authors.forename: Aritra
authors.initials: A
authors.lastname: Pal
authors.forename: Regine
authors.initials: R
authors.lastname: Herbst-Irmer