31P nuclear magnetic resonance study of the interaction of multidentate amines with zinc(II) bis( O,O′-di-iso-butyldithiophosphate)

Abstract

31P NMR has been employed to study the interaction between zinc(II) bis( O,O′-di-iso-butyldithiophosphate), Zn[S 2P(O iBu) 2] 2, and four multidentate amines (diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine) in chloroform at 294 K. The major interaction of Zn[S 2P(O iBu) 2] 2 and these polyamines involves displacement of the {S 2P(O iBu) 2} ligands from the zinc giving [Zn(amine)] 2+ and [S 2P(O iBu) 2] − ions in solution. The magnitudes of the equilibrium constants, K 1 (=[{Zn(amine)} 2+][{DDP} −] 2/[Zn(DDP) 2][amine]), have been evaluated in the cases of triethylenetetramine (20.0 l mol −1), tetraethylenepentamine (19.1 l mol −1) and pentaethylenehexamine (1.58 l mol −1). Crystalline 1:1 ionic complexes have also been isolated from these systems and characterised.