Synthesis, characterization and electrochemical behavior of oxo-bridged (arylimido)[tris(3,5-dimethylpyrazolyl)borato] molybdenum(V) complexes

Abstract

Locate full-text(opens in a new window)|Full Text(opens in a new window)|View at Publisher| Export | Download | Add to List | More... Inorganica Chimica Acta Volume 358, Issue 12, 1 August 2005, Pages 3303-3310 Synthesis, characterization and electrochemical behavior of oxo-bridged (arylimido)[tris(3,5-dimethylpyrazolyl)borato] molybdenum(V) complexes (Article) Topaloglu-Sozuer, I.a , Gunyar, A.a, Dulger-Irdem, S.a, Baya, M.b, Poli, R.b a Department of Chemistry, Faculty of Science, Izmir Institute of Technology, Gulbahce, Urla-35430, Izmir, Turkey b Laboratoire de Chimie de Coordination, UPR CNRS 8241, 205 Route de Narbonne, 31077 Toulouse Cedex, France View references (34) Abstract Reaction of the oxo-molybdenum(V) precursor [MoTp*(O)Cl2] [Tp* = hydrotris(3,5-dimethyl-1-pyrazolyl)borate] with H 2NC6H4R-4 (R = OEt; OPr) in refluxing toluene in the presence of Et3N afforded the binuclear oxo-bridged oxo(arylimido) molybdenum(V) complexes [Tp*Mo(O)Cl](μ-O) [Tp*Mo(NC6H4OR-4)Cl]. Surprisingly, a similar reaction between [MoTp*(O)Cl2] and C6H 5NH2 yielded the previously reported compound [{MoTp*(O)Cl}2(μ-O)] as the only product. The new compounds were characterized by microanalytical data, mass spectrometry, IR and 1H NMR spectroscopy. Cyclic voltammetric studies of the new compounds, of the previously reported compounds [Tp*Mo(O)Cl](μ-O)[Tp*Mo(NAr)Cl] (Ar = C6H4OMe-4, C6H 4F-3, C6H4Cl-4, C6H4Br-4, and C6H4I-3), and of [{MoTp*(O)Cl} 2(μ-O)] revealed a reversible one-electron oxidation process that is little affected by the nature of the substituent on the aryl group, whereas it is greatly affected by replacement of the imido ligand with an oxo ligand. The [{MoTp*(O)Cl}2(μ-O)] compound also shows a one-electron reduction process.