title: Syntheses, characterization, and catalytic ability in alkane oxygenation of chloro(dimethyl sulfoxide)ruthenium(II) complexes with tris(2-pyridylmethyl)amine and its derivatives.
abstract: New ruthenium(II) complexes having a tetradentate ligand such as tris(2-pyridylmethyl)amine (TPA), tris[2-(5-methoxycarbonyl)pyridylmethyl]amine [5-(MeOCO)3-TPA], tris(2-quinolylmethyl)amine (TQA), or bis(2-pyridylmethyl)glycinate (BPG) have been prepared. The reaction of the ligand with [RuCl2(Me2SO)4] resulted in a mixture of trans and cis isomers of the chloro(dimethyl sulfoxide-kappaS)ruthenium(II) complexes containing a TPA or a BPG, whereas a trans(Cl,N(amino)) isomer was selectively obtained for 5-(MeOCO)3-TPA and TQA. The trans and cis isomers of the [RuCl(TPA)(Me2SO)]+ complex were easily separated by fractional recrystallization. The molecular structures of trans- and cis(Cl,N(amino))-[RuCl(TPA)(Me2SO)]+ complexes and the trans(Cl,N(amino))-[RuCl{5-(MeOCO)3-TPA}(Me2SO)]+ complex have been determined by X-ray structural analyses. The reaction of TPA with [RuCl2(PhCN)4] gave a single isomer of the chloro(benzonitrile)ruthenium(II) complex, whereas the bis(benzonitrile)ruthenium(II) complex was obtained with BPG. The cis(Cl,N(amino))-[RuCl(TPA)(Me2SO)]+ complex is thermodynamically much less stable than the trans isomer and isomerizes in dimethyl sulfoxide at 65-100 degrees C. Oxygenation of alkanes catalyzed by these ruthenium(II) complexes has been examined. The chloro(dimethyl sulfoxide-kappaS)ruthenium(II) complexes with TPA and its derivatives using m-chloroperbenzoic acid as a cooxidant showed high catalytic ability. Adamantane was efficiently and selectively oxidized to give 1-adamantanol up to 88%. The chloro(dimethyl sulfoxide-kappaS)ruthenium(II) complex with 5-(MeOCO)3-TPA was found to be the most active catalyst among the complexes examined.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, Minami-osawa, Hachioji, Tokyo 192-0397, Japan. yamaguchi-motowo@c.metro-u.ac.jp
authors.forename: Motowo
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kousaka
authors.forename: Shinichi
authors.initials: S
authors.lastname: Izawa
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Ichii
authors.forename: Takashi
authors.initials: T
authors.lastname: Kumano
authors.forename: Dai
authors.initials: D
authors.lastname: Masui
authors.forename: Takamichi
authors.initials: T
authors.lastname: Yamagishi