title: First stabilization of 14-electron rhodium(I) complexes by hemichelation.
abstract: Hemichelation is emerging as a new mode of coordination where non-covalent interactions crucially contribute to the cohesion of electron-unsaturated organometallic complexes. This study discloses an unprecedented demonstration of this concept to a Group 9 metal, that is, Rh(I). The syntheses of new 14-electron Rh(I) complexes were achieved by choosing the anti-[(η(6):η(6)-fluorenyl){Cr(CO)3}2] anion as the ambiphilic hemichelating ligand, which was treated with [{Rh(nbd)Cl}2] (nbd=norbornadiene) and [{Rh(CO)2Cl}2]. The new T-shaped Rh(I) hemichelates were characterized by analytical and structural methods. Investigations using the methods of the DFT and electron-density topology analysis (NCI region analysis, QTAIM theory) confirmed the closed-shell, non-covalent and attractive characters of the interaction between the Rh(I) center and the proximal Cr(CO)3 moiety. This study shows that, by appropriate tuning of the electronic properties of the ambiphilic ligand, truly coordination-unsaturated Rh(I) complexes can be synthesized in a manageable form.
authors.affiliation: Institut de Chimie de Strasbourg, UMR 7177 CNRS, Université de Strasbourg, 4 rue Blaise Pascal, 67070 Strasbourg Cedex (France) http://lcsom.u-strasbg.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Werlé
authors.forename: Corinne
authors.initials: C
authors.lastname: Bailly
authors.forename: Lydia
authors.initials: L
authors.lastname: Karmazin-Brelot
authors.forename: Xavier-Frédéric
authors.initials: XF
authors.lastname: Le Goff
authors.forename: Michel
authors.initials: M
authors.lastname: Pfeffer
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Djukic
keywords: chromium; coordination modes; hemichelation; metal-metal interactions; rhodium