%0 Journal Article
%T Synthesis and Characterization of Novel <i>¦Ì</i>-Carbonato Tetranuclear Copper Complexes [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] in Aprotic Media
%A Mohamed A. El-Sayed
%A Hoda A. Elwakeil
%A Ahmed H. Abdel Salam
%A Hemmat A. Elbadawy
%J Open Journal of Inorganic Chemistry
%P 66-75
%@ 2161-7414
%D 2016
%I Scientific Research Publishing
%R 10.4236/ojic.2016.61004
%X In this work, novel oxidative coupling complexes, [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] (n = 1 or 2, X = Cl or Br, Pip = piperidine), are synthesized from the reaction of well characterized Lewis base [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>O<sub>2</sub>] with carbon dioxide as a Lewis acid in CH<sub>2</sub>Cl<sub>2</sub>. These carbonato-derivatives are isolated as stable solids. They are easily soluble in aprotic solvents as CH<sub>2</sub>Cl<sub>2</sub>or phNO<sub>2</sub>. Cryoscopic measurements support tetranuclear structure for all of them. Electronic spectra in the near infrared with high molecular absorptivity may be explained for tetranuclear cuban structure to fulfil 3 halo-ligands for each copper centre in [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>]. The EPR spectra for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] complexes are axial type of spectra (d<sub>x2-y2</sub> G.S) suggesting elongated tetragonal distortion for all of them. Cyclic voltammograms for [(Pip)<sub>4n</sub>Cu<sub>4</sub>X<sub>4</sub>(CO<sub>3</sub>)<sub>2</sub>] are irreversible in character. These tetranuclear carbonato complexes show catalytical activity. They initiate the oxidation of 2,6-dimethylphenol (DMP) to 3,3¡¯,5,5¡¯-tetramethyl-4,4¡¯-diphenoquinone (DPQ).
%K Complexes
%K Tetranuclear Cuban
%K Carbonato Bridge
%K Copper
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=62789