title: Spectroscopic investigations of bis(sulfoximine) copper(II) complexes and their relevance in asymmetric catalysis.
abstract: The structure of Cu(II) complex 3 formed within the course of a stereoselective Diels-Alder reaction was investigated by EXAFS, CW-EPR at X- and W-band, HYSCORE, pulsed ENDOR, and UV-vis spectroscopy. The experimental techniques indicate that the chiral bis(sulfoximine) ligand (S,S)-1 and the dienophile form a tetragonally distorted complex in CH(2)Cl(2). The ligand binds to the Cu(II) center via the imine nitrogens, whereas the dienophile interacts via the carbonyl oxygen atoms. The additional sites of the first coordination sphere are occupied by counterions and, presumably, solvent molecules. At the axial position, a triflate anion binds via an oxygen atom.
authors.affiliation: Institut für Organische Chemie der RWTH Aachen, Prof.-Pirlet-Strasse 1, Germany. georg.gescheidt@unibas.ch
authors.forename: Carsten
authors.initials: C
authors.lastname: Bolm
authors.forename: Marc
authors.initials: M
authors.lastname: Martin
authors.forename: Georg
authors.initials: G
authors.lastname: Gescheidt
authors.forename: Cornelia
authors.initials: C
authors.lastname: Palivan
authors.forename: Dmytro
authors.initials: D
authors.lastname: Neshchadin
authors.forename: Helmut
authors.initials: H
authors.lastname: Bertagnolli
authors.forename: Martin
authors.initials: M
authors.lastname: Feth
authors.forename: Arthur
authors.initials: A
authors.lastname: Schweiger
authors.forename: George
authors.initials: G
authors.lastname: Mitrikas
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Harmer