Fast reactions at planar four-co-ordinate complexes. Part II. The leaving-group effect in palladium(II) complexes of 3-azapentane-1,5-diamine

Abstract

The displacement of ligand X in [Pd(3-NHpd)X]⁺(3-NHpd = 3-azapentane-1,5-diamine) by a variety of nucleophiles Y has been studied in methanol at 25° C and I= 0·1 M(X = Cl^–, Br^–, I^–, N₃^–, or NO₂^–; Y = Cl^–, Br^–, N₃^–, I^–, SCN^–, or thiourea). The results show that, in spite of the large difference in reactivity between analogous palladium(II) and platinum(II) complexes, the lability sequence is almost the same, and, as in the case of Pt^II complexes, there are indications that the free-energy changes related to bond formation and weakening during the formation of the transition state are largely independent indicating that these processes are asynchronous in nature.