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 · n H 2 O (M = Ni, n = 6; Cu, n = 0), Mn(5-Acqo) 3 ·H 2 O, 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 2 O. 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 . 1 H NMR and/or 13 C 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.