Reactions of Copper(II) Chloride in Solution: Facile Formation of Tetranuclear Copper Clusters and Other Complexes That Are Relevant in Catalytic Redox Processes. Issue 17 (28th February 2013)

• Record Type: Journal Article
• Authors: Löw, Sabine; Becker, Jonathan; Würtele, Christian; Miska, Andreas; Kleeberg, Christian; Behrens, Ulrich; Walter, Olaf; Schindler, Siegfried
• Is Part Of: Chemistry. Volume 19:Issue 17(2013)
• Page Start: 5342
• Page End: 5351
• Publication Date: 2013-02-28
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201203848
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Mixing CuCl<sub>2</sub><bold>⋅</bold>2 H<sub>2</sub>O with benzylamine in alcoholic solutions led to an extremely colorful chemistry caused by the formation of a large number of different complexes. Many of these different species could be structurally characterized. These include relatively simple compounds such as [Cu(L<sup>1</sup>)<sub>4</sub>Cl<sub>2</sub>] (L<sup>1</sup>=benzylamine) and (HL<sup>1</sup>)<sub>2</sub>[CuCl<sub>4</sub>]. Most interestingly is the easy formation of two cluster complexes, one based on two cluster units Cu<sub>4</sub>OCl<sub>6</sub>(L<sup>1</sup>)<sub>4</sub> connected through one [Cu(L<sup>1</sup>)<sub>2</sub>Cl<sub>2</sub>] complex and one based on a cubane‐type cluster ([Cu<sub>4</sub>O<sub>4</sub>](C<sub>11</sub>H<sub>14</sub>)<sub>4</sub>Cl<sub>4</sub>). Both clusters proved to be highly reactive in a series of oxidation reactions of organic substrates by using air or peroxides as oxidants. Furthermore, it was possible to isolate and structurally characterize ([Cu(L<sup>1</sup>)Cl]<sub>3</sub> and [Cu(benz<sub>2</sub>mpa)<sub>2</sub>]CuCl<sub>2</sub> (benz<sub>2</sub>mpa=benzyl‐(2‐benzylimino‐1‐methyl‐propylidene)‐amine), two copper(I) complexes that formed in solution, demonstrating the high redox activity of the cluster systems. In addition, it was possible to solve the molecular structures of the compounds Cu<sub>4</sub>OCl<sub>6</sub>(MeOH)<sub>4</sub>, [Cu(MeOH)<sub>2</sub>Cl<sub>2</sub>], [Cu(aniline)<sub>2</sub>Cl<sub>2</sub>], and an organic side product (HC<sub>13</sub>H<sub>19</sub>NOCl). In fact all determined structures are of a known type but the chemical relation between these compounds could be explained for the first time. The paper describes these different compounds and their chemical equilibria. Some of these complexes seem to be relevant in catalytic oxidation reactions and their reactivity is discussed in more detail.</p> </abstract>