Coordination compounds of substituted 1,10-Phenanthrolines and related dipyridyls. V. Complexes of cobalt and 2,9-Dimethyl-1,10-phenanthroline

Abstract

A series of complexes of cobalt(II) and 2,9-dimethyl-1,10-phenanthroline (dmp) has been prepared. Complexes of formula CoX₂dmp (X = Cl, Br, I, KCS) are monomeric in acetone and camphor and non-electrolytes in nitrobenzene and nitromethane. The magnetic moments and visible absorption spectra favour the assignment of tetrahedral stereochemistry about the Co atom. Complexes containing 2 moles dmp per Co appear to have octahedral arrangements of ligands about the Co atom. These are of the type [CoNO₃(H₂O)dmp₂]X, (X = NO₃, ClO₄, BPh₄) and Co(NCS)₂dmp₂. The magnetic moments, visible and infrared spectra, and conductances in nitrobenzene and nitromethane support this conclusion. With other mono-dmp complexes (CoX₂dmp, X = NO₃, ½SO₄) and bis-dmp complexes {CoXdmp,ClO₄,H₂O (X = Cl, Br) ; Codmp₂(ClO₄)₂}, stereochemical assignments could not be made.