Complexes of cobalt(II) nitrite with amine ligands

Abstract

The preparations, i.r. and electronic spectra, and magnetic moments of a range of cobalt(II) nitrite-complexes with amine ligands are reported. In all cases the nitrite-groups co-ordinate through oxygen, as unidentate nitrite-groups in [Co(pyridine)₄(ONO)₂],2(pyridine), CoL₄(ONO)₂ where L = isoquinoline or 4-methylpyridine, and Co(diamine)₂(ONO)₂ where diamine =NN-dimethyl- or NN′-diethyl-ethylenediamine, but as chelating nitrite groups in Co(NNN′N′-tetramethylethylenediamine)(NO₂)₂ and in various 3:1 and 2:1 complexes with heterocyclic amines. Distorted seven co-ordination is suggested for the metal ion in the compounds CoL₃(NO₂)₂ where L = pyridine or 3-methylpyridine.