Stabilities of complex compounds of metals in non-aqueous solutions

Abstract

By defining the successive stability constants of metal complex compounds in terms of generalised equilibria it is possible to study metals which do not form simple hydrated metal ions and also non-water soluble ligands and complexes. If the equilibrium constants are to be interpreted in terms of bond energies etc. it is necessary that the system be defined. That is, the real compositions of the compounds in the equilibrium solution should be known. Some important types of interfering dissociations and reactions can be detected by means of electrical conductivity measurements and some results of such measurements are outlined. The system [PdCl2 (n-C8H17NH2)2] + PBu3n = [PdCl2 (n-C8H17NH2) (PBu3n) ] +C8H17NH2 [PdCl2 (n-C8H17NH2) (PBu3n)] + PBu3n = [PdCl2(PBu3n)2] + C8H17NH2 has been studied and the free energy changes for the replacement of n-octylamine by tri-n-butylphosphine in the two stages are: ΔG1 = −4.56 to −5.08 kcal. ΔG2 =−5.30 to −5.92 kcal.