Kinetic and spectroscopic studies with a rapid-scanning spectrometer. Part 1. Transient intermediates in the dissociation of nickel(II) polyamine complexes

Abstract

Successive stages in the acid-catalysed aquation of several polyamine chelates of Ni^II have been characterised both optically and kinetically by means of a rapid-scanning spectrometer. Complete spectra of several new transient intermediates are reported and assigned. When two terdentate ligands, viz. diethylenetriamine (dien), are involved it is established that one is completely removed in two stages before the second starts to disengage. The stepwise acid dissociation of the [Ni(trien)(OH₂)₂]²⁺ ion (trien = triethylenetetramine) is shown to be much more complex than had previously been indicated.