title: Controlling the coordination modes of a new and highly flexible ligand bearing two N-heterocyclic carbene moieties at a bipyridine backbone.
abstract: A new and highly flexible biscarbene ligand with two imidazolin-2-ylidene moieties in 6,6'-position of a 2,2'-bipyridine was prepared and structurally characterised by X-ray analysis. Various silver complexes were prepared from the imidazolium salts. Depending on the counterion, the coordination mode of the ligand can be mono- or bidentate. Pd complexes are feasible directly from the imidazolium salt using palladium(II)-acetate or via transmetallation from silver carbene complexes with [PdCl(2)(CH(3)CN)(2)] or [PdCl(2)(COD)]. Controlled by the structure of the silver complexes the biscarbenebipyridine ligand is a di- or tetracoordinating ligand forming mono- or dinuclear complexes. The high flexibility of this ligand is confirmed by transmetallation from silver to copper, which results in formation of a dinuclear copper complex with two bridging biscarbene ligands.
authors.affiliation: Organisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, Im Neuenheimer Feld 270, D-69120, Heidelberg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Deissler
authors.forename: Frank
authors.initials: F
authors.lastname: Rominger
authors.forename: Doris
authors.initials: D
authors.lastname: Kunz
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D008024:Ligands; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D006571:Heterocyclic Compounds; D007093:Imidazoles; D008024:Ligands; D009942:Organometallic Compounds; C030011:carbene; D012834:Silver; D015082:2,2'-Dipyridyl; D010165:Palladium; D003300:Copper; D008697:Methane