@Article{Lebrini_etal2011, author="Lebrini, M. and Mbomekall{\'e}, I.M. and Dolbecq, A. and Marrot, J. and Berthet, P. and Ntienoue, J. and S{\'e}cheresse, F. and Vigneron, J. and Etcheberry, A.", title="Manganese(III)-containing wells-dawson sandwich-type polyoxometalates: Comparison with their manganese(II) counterparts", journal="Inorganic Chemistry", year="2011", volume="50", number="14", pages="6437--6448", abstract="We present the synthesis and structural characterization, assessed by various techniques (FTIR, TGA, UV-vis, elemental analysis, single-crystal X-ray diffraction for three compounds, magnetic susceptibility, and electrochemistry) of five manganese-containing Wells-Dawson sandwich-type (WDST) complexes. The dimanganese(II)-containing complex, [Na2(H2O) 2MnII2(As2W15O 56)2]18- (1), was obtained by reaction of MnCl2 with 1 equiv of [As2W15O 56]12- in acetate medium (pH 4.7). Oxidation of 1 by Na2S2O8 in aqueous solution led to the dimanganese(III) complex [Na2(H2O)2Mn III2(As2W15O56) 2]16- (2), while its trimanganese(II) homologue, [Na(H2O)2MnII(H2O)Mn II2(As2W15O56) 2]17- (3), was obtained by addition of ca. 1 equiv of MnCl2 to a solution of 1 in 1 M NaCl. The trimanganese(III) and tetramanganese(III) counterparts, [MnIII(H2O)Mn III2(As2W15O56) 2]15- (4) and [MnIII2(H 2O)2MnIII2(As2W 15O56)2]12- (6), are, respectively, obtained by oxidation of aqueous solutions of 3 and [MnII2(H2O)2MnII2(As 2W15O56)2]16- (5) by Na2S2O8. Single-crystal X-ray analyses were carried out on 2, 3, and 4. BVS calculations and XPS confirmed that the oxidation state of Mn centers is +II for complexes 1, 3, and 5 and +III for 2, 4, and 6. A complete comparative electrochemical study was carried out on the six compounds cited above, and it was possible to observe the distinct redox steps MnIV/III and MnIII/II. Magnetization measurements, as a function of temperature, confirm the presence of antiferromagnetic interactions between the Mn ions in these compounds in all cases with the exception of compound 2. {\textcopyright} 2011 American Chemical Society.", optnote="Export Date: 21 October 2011; Source: Scopus; Coden: Inoca; doi: 10.1021/ic102237x; Language of Original Document: English; Correspondence Address: Mbomekall{\'e}, I.M.; Institut Lavoisier de Versailles, UMR 8180, CNRS Universit{\'e} de Versailles Saint-Quentin, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France; email: israel.mbomekalle@chimie.uvsq.fr", optnote="exported from refbase (http://php.ecofog.gf/refbase/show.php?record=346), last updated on Fri, 21 Oct 2011 11:12:22 -0300", issn="00201669 (Issn)", opturl="http://www.scopus.com/inward/record.url?eid=2-s2.0-79960275926&partnerID=40&md5=982e219e7e1a2f79e626a639ae89708b" }