Formation of the {Cu_3~(II)(mu_3-OH)}~(5+) 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)

摘要

Reactions of [Cu_2(O_2CMe)_4(H_2O)_2] or Cu(O_2CPh)_2 centre dot 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)(mu_3-OH)(O_2CR)_2{(py)_2CNO}_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.