The coordination environment around CuII in highly concentrated solutions of copper(II) salts (CuCl2 and Cu(Tf2N)2) in two pure ionic liquids bearing the same anion, namely, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([bmim][Tf2N]) and 1-butyl-3-methylimidazolium chloride ([bmim]Cl), is investigated by X-ray photoelectron spectroscopy (XPS), UV/Vis spectroscopy, EPR spectroscopy and DFT calculations. Moreover, the electrochemical behavior of these mixtures is studied. Whereas reversible reduction of CuII to copper metal can be observed in the 1:1 [bmim][Tf2N]:Cu(Tf2N)2 solution, 2:1 and 1:1 [bmim]Cl:CuCl2 mixtures showed one-electron reduction of CuII to CuI with formation of a permanent deposit of CuCl. XPS, UV/Vis and EPR spectra as well as DFT calculations suggest the formation in [bmim]Cl of dynamic coordination complexes arising from the interaction between CuCl2 and [bmim]+Cl- . The two long-lived situations are probably trigonal and deformed tetrahedral copper(II) chloride coordination complexes ([CuCl3]- and [CuCl4]2-, respectively).
|Autori:||Stefano Caporali; Cinzia Chiappe; Tiziana Ghilardi; Pomelli Christian Silvio; . Calogero Pinzino|
|Titolo:||Coordination Environment of Highly Concentrated Solutions of Cu(II) in Ionic Liquids through a Multidisciplinary Approach|
|Anno del prodotto:||2012|
|Digital Object Identifier (DOI):||10.1002/cphc.201100876|
|Appare nelle tipologie:||1.1 Articolo in rivista|