Complexes of manganese(III), cobalt(III), iron(II), nickel(II) and copper(II) with 5-acetylamino-1,2-benzoquinone-2-oxime

Abstract

Nitrosation of 3-acetylaminophenol in the presence of the appropriate metal(II) chloride or Na 3[Co(NO 2) 6] has led to the complexes M(5-Acqo) 2· nH 2O (M = Ni, n = 6; Cu, n = 0), Mn(5-Acqo) 3·H 2O, Na[Fe(5-Acqo) 3] and Na[Co(5-Acqo) 2(NO 2) 2] (AcqoH = 5-acetylamino-1,2-benzoquinone-2-oxime). Co(5-Acqo) 3 resulted from the reaction of 5-AcqoH with CoCl 2·6H 2O. The reaction of M(5-Acqo) 2 with pyridine and 2,2′-dipyridine afforded the adducts M(5-Acqo) 2(py) 2 and M(5-Acqo) 2(dipy), respectively. Solution electronic spectra and magnetochemical studies indicated octahedral geometries for all compelxes prepared, except Cu(5-Acqo) 2. 1H NMR and/or 13C NMR studies indicated that Co(5-Acqo) 3 exists as a mixture of the meridional and facial isomers, whereas the anion in Na[Fe(5-Acqo) 3] is entirely in the meridional form.