Five-co-ordinate palladium(II). An examination of the electronic spectra of some trigonal-bipyramidal complexes containing a compressed palladium–antimony linkage

Abstract

The trisubstituted stibine, tris(o-dimethylarsinophenyl)stibine, sbtas, forms complexes of type [Pd(sbtas)X]Y (X = Cl, Br, I, SCN; Y = Cl, CNS, BPh₄) which are five-co-ordinate and trigonal bipyramidal. The electronic spectra of these complexes show a shift of the ligand-field bands to higher energy in the order I^– > Br^– > Cl^–, and this nephelauxetic behaviour is discussed in relation to the compression of the Pd–Sb linkage as a result of chelation.