title: Conformationally dynamic titanium and zirconium cationic complexes of bis(naphthoxy)pyridine ligands: structure, "oscillation" and olefin polymerization catalysis.
abstract: Discrete ionic complexes {ONOSiMe2tBu}M(CH2Ph)((η6-Ph)CH2B(C6F5)3) (M = Ti, 2-Ti; Zr, 2-Zr) have been prepared from the parent neutral dibenzyl precursors and B(C6F5)3. Also, a neutral dichloro complex {ONOSiMe2tBu}ZrCl2(Me2NH) (3) was synthesized by the reaction of a proligand {ONOSiMe2tBu}H2(1-H2) with (Me2N)2ZrCl2(DME). The compounds were characterized by NMR spectroscopy and X-ray crystallography (for 2-Zr and 3). In the solid state, both 2-Zr and 3 feature meso-like binding of the ligand. VT NMR studies of 2-Ti and 2-Zr revealed that the former species dissociates in solution to form an outer-sphere ion pair (OSIP) that features a complicated dynamic behavior, while the latter compound retains an inner-sphere ion pair (ISIP) structure that interconverts between Cs-symmetric (meso-like) and C1-symmetric (rac-like) conformations. The mechanism of this interconversion was assessed by DFT calculations and the corresponding barrier for the straightforward interconversion was calculated ().
authors.affiliation: Université de Rennes 1, CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, F-35042 Rennes Cedex, France. jean-francois.carpentier@univ-rennes1.fr evgueni.kirillov@univ-rennes1.fr.
authors.forename: Liana
authors.initials: L
authors.lastname: Annunziata
authors.affiliation: Université de Rennes 1, CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, F-35042 Rennes Cedex, France. jean-francois.carpentier@univ-rennes1.fr evgueni.kirillov@univ-rennes1.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Roisnel
authors.affiliation: Total Petrochemicals Research, Zone Industrielle C, B-7181 Feluy, Belgium.
authors.forename: Abbas
authors.initials: A
authors.lastname: Razavi
authors.affiliation: Université de Rennes 1, CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, F-35042 Rennes Cedex, France. jean-francois.carpentier@univ-rennes1.fr evgueni.kirillov@univ-rennes1.fr.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Carpentier
authors.affiliation: Université de Rennes 1, CNRS, Institut des Sciences Chimiques de Rennes, UMR 6226, F-35042 Rennes Cedex, France. jean-francois.carpentier@univ-rennes1.fr evgueni.kirillov@univ-rennes1.fr.
authors.forename: Evgueni
authors.identifier: http://orcid.org/0000-0002-5067-480X
authors.initials: E
authors.lastname: Kirillov