Factors involved in the electronic mobility within the chelate ring of the linkage isomers of Co(II), Ni(II) and Cu(II) complexes with vicinal oxime-imine ligands; An IR study

Abstract

Abstract The electron mobility in the five- and six-membered chelate rings of the LM complexes [H 2 L = N , N ′-ethylenebis(isonitrosoacetylacetoneimine); M = divalent Ni, Co or Cu ions] is discussed in relation to the stability of the chelate isomers. The vibrational energies of the NO, CN and CO binding are related to the second or third ionization potential of the metal ions. This relationship is used for the calculation of ν (NO), ν (CN) and ν (CO) of a metal complex from the data of a prepared metal complex. The role of non-coordinated carbonyl group is discussed in relation to the imine nephelauxetic power which accounts for: (a) the conversion of the chelate isomer; and (b) the surprising stability of both modes of coordination by the oximato group in bis(4-iminopentane-2,3-dione 3-oximato) nickel(II).