Formation of the [formula omitted] core in copper(II) carboxylate chemistry via use of di-2-pyridyl ketone oxime [(py) 2CNOH] : [Cu 3(OH)(O 2CR) 2{(py) 2CNO} 3] (R = Me, Ph)

Abstract

Reactions of [Cu 2(O 2CMe) 4(H 2O) 2] or Cu(O 2CPh) 2 · 2H 2O with 2 or 1, respectively, molar equivalents of di-2-pyridyl ketone oxime, (py) 2CNOH, in MeCN-based solvent mixtures yield complexes [ Cu 3 II ( μ 3 -OH ) ( O 2 CR ) 2 { ( py ) 2 CNO } 3 ] ( 1, R = Me; 2, R = Ph). Crystal structures of these compounds show similar triangles of Cu II ions, centered by a triply bridging hydroxo ligand and with three edge-bridging oximate groups from the three 2.1110 (py) 2CNO − ions. Preliminary variable-temperature magnetic susceptibility studies and EPR data at 4.2 K for 1 reveal an antiferromagnetically-coupled system showing antisymmetric exchange.