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

Abstract

The preparation, crystal structure and reactivity of a trimetallic Mn III carboxylate cluster containing the dianion of methylsalicyloxime (Me-saoH 2), is reported. The reaction between Mn(OAc) 2 · 4H 2O and Me-saoH 2 in pyridine (py) produces the complex [ Mn 3 III O ( OAc ) ( Me-sao ) 3 ( py ) 4 ] · 2 py ( 1 · 2py ) in very good yields. The neutral complex consists of a central triangular { Mn 3 III O } unit assembled together by three η 1:η 1:η 1:μ 2-oximato(−2) and one bridging AcO − ligands. Oxidation of 1 · 2 py in MeCN in the presence of (NH 4) 2[Ce IV(NO 3) 6] leads to the formation of complex [ Mn 4 IV Ce 2 III O 2 ( Me-sao ) 6 ( NO 3 ) 4 ( OAc ) 2 ( H 2 O ) 2 ] · 6 MeCN ( 2 · 6MeCN ) . Its centrosymmetric structure may be described as two { Mn 2 IV Ce III O } triangles linked through two η 2:η 2:η 1:μ 4 oximato(−2) ligands. Each { Mn 2 IV Ce III O } unit is held together via one η 2:η 1:η 1:μ 3 and one η 1:η 1:η 1:μ 2-Me-sao 2− ligand, and one bridging acetate. Dc magnetic susceptibility studies reveal the presence of dominant antiferromagnetic interactions in both complexes.