Triangular Ni(II) complexes from the use of 2-pyridyl oximes

Abstract

The reactions of representative 2-pyridyl oximes with Ni II salts in the presence of a base have been investigated. The synthetic study has led to the new triangular complexes [Νi 3(ppko) 6]·2H 2O·0.5EtOH·MeOH ( 1·2H 2O·0.5EtOH·MeOH), [Νi 3(mpko) 3(HCO 2) 2(mpkoH) 2](ClO 4) ( 2) and [Νi 3(ppko) 3(HCO 2) 2(ppkoH) 2](ClO 4) ( 3), where ppko − is the anion of phenyl(2-pyridyl)ketone oxime and mpko − is the anion of methyl(2-pyridyl)ketone oxime. The structures of compounds 1 and 2 have been determined by single crystal X-ray diffraction. The ppko − ligand in 1 adopts four different coordination modes including the unique N pyridylO oximate chelating one which gives rise to a 6-membered chelating ring, while the neutral and the deprotonated oxime ligands in 2 adopt three different coordination modes. The magnetic properties of 1 and 2 have been studied by variable-temperature dc magnetic susceptibility techniques which indicate antiferromagnetic interactions.