title: A heterobimetallic superoxide complex formed through O2 activation between chromium(II) and a lithium cation.
abstract: The reaction of 1,1,3,3-tetraphenyl-1,3-disiloxandiol (LH2) with n-butyllithium and CrCl2 results in a mononuclear chromium(II) complex (1) that further reacts with O2 at low temperatures to yield a mononuclear chromium(III) superoxide complex [L2CrO2(THF)][Li2(THF)3] (2). The crystal structure revealed that the chromium superoxido entity is stabilized by the coordination to an adjacent lithium cation. Complex 2 thus contains an unprecedented heterobimetallic [Cr(III)(μ-O2)Li(+)] core; beyond this it is the first chromium superoxide for which a temperature-dependent magnetic characterization could be achieved, and the first structurally characterized representative with chromium in an exclusive O-donor environment.
authors.affiliation: Humboldt-Universität zu Berlin, Institut für Chemie, Brook-Taylor-Strasse 2, 12489 Berlin (Germany) http://www.chemie.hu-berlin.de/aglimberg.
authors.forename: Fabian
authors.initials: F
authors.lastname: Schax
authors.forename: Simon
authors.initials: S
authors.lastname: Suhr
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Beatrice
authors.initials: B
authors.lastname: Braun
authors.forename: Christian
authors.initials: C
authors.lastname: Herwig
authors.forename: Christian
authors.initials: C
authors.lastname: Limberg
keywords: Lewis acid; chromium; dioxygen activation; siloxides; superoxide