The use of methylsalicyloxime in manganese chemistry:: A [Mn3III] triangle and its oxidation to a [MnIV4CeIII2] rod

The preparation, crystal structure and reactivity of a trimetallic Mn-III carboxylate cluster containing the dianion of meth-ysalicyloxime (Me-saoH(2)), is reported. The reaction between Mn(OAC)2 center dot 4H(2)O and Me-saoH2 in pyridine (py) produces the complex [(Mn3O)-O-III(OAc)(Me-sao)3(py)4]center dot 2py (1 center dot 2py) in very good yields. The neutral complex consists of a central triangular {(Mn3O)-O-III} unit assembled together by three eta(1):eta(1):eta(1):mu(2)-oximato(-2) and one bridging AcO- ligands. Oxidation of 1 center dot 2 py in MeCN in the presence of (NH4)(2)[Celv(NO3)6] leads to the formation of complex [(Mn4Ce2III)-Ce-IV,O-2(Me-sao),(NO3),(OAc)2(H2O)2]center dot 6MeCN (2 center dot 6MeCN). Its cen trosymmetric structure may be described as two {(Mn2CeO)-Ce-IV-O-III} triangles linked through 1:114 oximato(-2) ligands. Each {(Mn2CeO)-Ce-IV-O-III} unit is held together via one eta(2): eta(1):eta(1):mu(3) and one eta(1):eta(1):eta(1):mu(2)-Me-sao(2-) ligand, and one bridging acetate. Dc magnetic susceptibility studies reveal the presence of dominant antiferromagnetic interactions in both complexes. (c) 2007 Elsevier B.V. All rights reserved.