Complexes of bis(hexafluoroacetylacetonato)copper(II) with some nitrogen-containing chelates and ethylene glycol

Abstract

Complexes of bis(hexafluoroacetylacetonato)copper(II), Cu(hfac)₂, with bidentate and potentially chelating ligands have been prepared. Monomeric addition complexes Cu(hfac)₂L have been isolated where L =o-phenanthroline, 2,2′-bipyridyl, ethylenediamine, ethylene glycol, NN′- and NN-dimethylethylenediamines, NNN′N′-tetramethyl-ethylenediamine, NNN′N′-tetramethyl-o-phenylenediamine, and NN′-dimethylpiperazine. Cu(hfac)₂L₂ complexes have been isolated for L = ethylenediamine, NN′- and NN-dimethylethylenediamine, and NN′-dibenzylethylenediamine.

The diffuse reflectance spectra and i.r. spectra of these compounds are recorded, and provide evidence for six-fold distorted octahedral co-ordination of copper(II) in the 1 : 1 complexes with the nitrogen-containing ligands, but for only five-co-ordination with ethylene glycol. In the 1 : 2 complexes the copper is co-ordinated by four coplanar nitrogen atoms from the two chelated diamines, and octahedral co-ordination is completed by oxygen atoms from monodentate β-diketonates.