title: Synthesis and coordinating ability of an anionic cobaltabisdicarbollide ligand geometrically analogous to BINAP.
abstract: The anionic chelating ligand [1,1'-(PPh2)2-3,3'-Co(1,2-C2B9H10)2]- has been synthesized from [3,3'-Co(1,2-C2B9H11)2]- in very good yield in a one-pot process with an easy work-up procedure. The coordinating ability of this ligand has been studied with Group 11 metal ions (Ag, Au) and with transition-metal ions (Pd, Rh). The two dicarbollide halves of the [1,1'-(PPh2)2-3,3'-Co(1,2-C2B9H10)2]- ligand can swing about one axis in a manner analogous to the constituent parts of BINAP and ferrocenyl phosphine derivatives. All these ligands function as hinges, with the most important property in relation to the coordination requirements of the metal being the PP distance. [1,1'-(PPh2)2-3,3'-Co(1,2-C2B9H10)2]-, BINAP, ferrocenyl phosphine derivatives, and other hinge ligands present a range of different PP separations, and consequently different coordination spheres and dispositions around metal cations. To account for these differences, the equation Dphi2 = D02 + 4 R2cos2(90-phi/2) has been developed. It relates the PP distance (Dphi) in a complex with the minimum PP distance (D0) that is characteristic of the hinge-type ligand.
authors.affiliation: Institut de Ciència de Materials de Barcelona (C.S.I.C.), Campus de la U.A.B. 08193 Bellaterra, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Rojo
authors.forename: Francesc
authors.initials: F
authors.lastname: Teixidor
authors.forename: Clara
authors.initials: C
authors.lastname: Viñas
authors.forename: Raikko
authors.initials: R
authors.lastname: Kivekäs
authors.forename: Reijo
authors.initials: R
authors.lastname: Sillanpää
mesh_terms: D001896:Boron Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002414:Cations, Monovalent / Q000737:chemistry; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry; D018360:Crystallography, X-Ray; D006046:Gold / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009281:Naphthalenes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry; D012238:Rhodium / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: C406943:BINAP, 2-naphthol; D001896:Boron Compounds; D002414:Cations, Monovalent; D002614:Chelating Agents; D009281:Naphthalenes; D009942:Organometallic Compounds; D012834:Silver; D010165:Palladium; D006046:Gold; D012238:Rhodium