title: Unusual mixed valent FeIIIFeII complex (St = 3/2) stabilised by a reduced bulky 1,2-diketone.
abstract: The reduction of the bulky 1,2-diketone bis(2,6-diisopropylphenyl)glyoxal () and FeBr(2) with 1.5 equivalents of Na results in a Class 2 mixed valent H.S. Fe(II) L.S. Fe(III) complex (2) with two five-coordinate Fe centres which are antiferromagnetically exchange-coupled to give a total spin S(t) = 3/2 ground state and an S(t) = 5/2 excited state that are separated by about 25 cm(-1) (for Delta(J) approximately 5J).
authors.affiliation: MPI für Bioanorganische Chemie, Stiftstrasse 34-36, Mülheim an der Ruhr, 45470, Germany.
authors.forename: Geoffrey H
authors.initials: GH
authors.lastname: Spikes
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Thomas
authors.initials: T
authors.lastname: Weyhermüller
authors.forename: Karl
authors.initials: K
authors.lastname: Wieghardt
mesh_terms: D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D006037:Glyoxal / Q000031:analogs & derivatives* / Q000737:chemistry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008280:Magnetics; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet; D015204:Spectroscopy, Mossbauer
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D007202:Indicators and Reagents; C525944:bis(2,6-diisopropylphenyl)glyoxal; D006037:Glyoxal