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BY-NC-ND 3.0 license Open Access Published by De Gruyter December 4, 2012

Complexes of germanium chlorides (RnGeCl4-n, n=0-3; R=Me, Ph) with redox active N-hetero­aromatic ligands: an electrochemical study

  • Mamadou Dieng , Diariatou Gningue-Sall and Viatcheslav Jouikov EMAIL logo

Abstract

Methyl and phenyl germanium chlorides (RnGeCl4-n, n=1, 2, 3), just like GeCl4, form complexes with electroactive bidentate (2,2'-bipyridine) and monodentate (imidazole, pyrimidine and 2,6-dichloro-pyridine) ligands, RnGeCl4-n‧Lx (x=1 or 2 for bi- and monodentate Ls, respectively), which were studied by cyclic voltammetry and electron paramagnetic resonance (EPR) spectroscopy supported by density functional theory (DFT) calculations. Dative interactions of lone pair of N of these heteroaromatic ligands towards Ge lower the reduction potential Ep of such complexes by about 1 V compared to own reduction potential Eo of L. Electron transfer to these complexes is reversible, resulting in corresponding anion radicals. Elimination of Cl- anion from these species leads to L-coordinated radicals whose one-electron reduction is also reversible. Real-time, time-dependent EPR spectro­electrochemistry of electrogenerated anion radicals of complexes with 2,2'-bipyridine (bipy) has shown that spin in these species is delocalized on the bipy moiety; nitrogen hfc constants suggest that two N atoms are non-equivalent and occupy different positions in the Ge environment. These findings are supported by DFT calculations.


Corresponding author: Viatcheslav Jouikov, Laboratory of Molecular Chemistry and Photonics, UMR 6226 ISCR, University of Rennes 1, F-35042 Rennes, France

Received: 2012-10-4
Accepted: 2012-11-1
Published Online: 2012-12-04
Published in Print: 2012-12-01

©2012 by Walter de Gruyter Berlin Boston

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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