title: Phosphenium Versus Pro-Phosphide Character of P-tert-butyl-dicyclopropeniophosphine: Zwitterionic Palladate Complexes of a Dicationic Phosphido Ligand.
abstract: With the view to enhancing the unique coordinating ability of the known phenyl-tetrakis(diisopropylamino)dicyclopropeniophosphine (Ph-DCP), replacement of the phenyl substituent by a tert-butyl substituent was envisaged. Both α-dicationic R-DCP phosphines, with R = Ph andtBu, were prepared in 54%-55% yield by substitution of RPCl2with two equivalents of bis(diisopropylamino)-dicyclopropenylidene (BAC) and metathesis with NaBF4. This method is implicitly consistent with the representation of R-DCPs as BAC-phosphenium adducts. The R-DCP salts were found to coordinate hard and soft Lewis acids such as a promoted oxygen atom (in the singlet spin state) in the corresponding R-DCP oxides, and electron-rich transition-metal centers in η1-R-DCP complexes with AuCl, PtCl3-, or PdCl3-, respectively. Coordination of Ph-DCP with PdCl2, which is a more electron-deficient Pd(II) center, leads to pentachlorinated dinuclear complexes [(Ph-DCP)PdCl2]2Cl-, where the dicoordinate Cl-bridge screens the repelling pairs of positive charges from each other. The same behavior is inferred for thetBu-DCP ligand, from which addition of an excess of (MeCN)2PdCl2was found to trigger a heterolytic cleavage of the DCP-tBu bond, releasingtBu+and a dicationic phosphide, DCP-: the latter is evidenced as a ligand in a tetranuclear complex ion [(μ2-DCP-)Pd2Cl4]2, which, upon HCl treatment, dissociates to a doubly zwitterionic dipalladate complex. All the complexes were isolated in 82%-97% yield, and five of them were characterized by X-ray crystallography.
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Cleve Dionel
authors: CD
authors: Mboyi
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Carine
authors: C
authors: Maaliki
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Amelle
authors: A
authors: Mankou Makaya
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Yves
authors: Y
authors: Canac
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Carine
authors: C
authors: Duhayon
authors: Laboratoire de Chimie de Coordination (LCC), CNRS , 205, route de Narbonne, F-31077 Toulouse, France.|Universite Toulouse III Paul Sabatier (UPS), Institut National Polytechnique (INP), Laboratoire de Chimie de Coordination (LCC), Université de Toulouse , F-31077 Toulouse, France.
authors: Remi
authors: R
authors: Chauvin