Electrochemical measurements in the solvents hexamethylphosphoric triamide and hexamethylthiophosphoric triamide

Abstract

Changes in half-wave potentials versus bis(biphenyl)chromium, Gibbs free energies of transfer for cations and the solvatochromic shift of acetylacetonato(N,N,N′,N′-tetramethylethyl-enediamine)copper(II) perchlorate, bis(cyano)bis(1,10-phenanthroline)iron(II) as well as bis(cyano)bis(3,4,7,8-tetramethyl-1,10-phenanthroline)iron(II) have been employed to study the Lewis-type donor and acceptor properties of hexamethylphosphoric triamide and hexamethylthiophosphoric triamide. The differing interactions of hexamethylphosphoric triamide and hexamethylthiophosphoric triamide with Na⁺, Tl⁺, Ag⁺ and Cd²⁺ are discussed within the concept of ‘hard’ and ‘soft’ acids and bases.

Polarographic and voltammetric data are given for NaClO₄, KClO₄, RbClO₄, CsClO₄, Ba(ClO₄)₂, TlClO₄, Zn(CF₃SO₃)₂, Cd(CF₃SO₃)₂, Cu(CF₃SO₃)₂, (NiClO₄)₂·2H₂O, Pb(CF₃SO₃)₂ oxygen, perylene, ferrocene and bis(biphenyl)chromium(I) tetraphenylborate in hexamethylphosphoric triamide and for LiClO₄, NaB(C₆H₅)₄, TlClO₄, Ag(CF₃SO₃), Zn(CF₃SO₃)₂, Cd(CF₃SO₃)₂, Cu(CF₃SO₃), Co(CF₃SO₃)₂, Ni(ClO₄)₂)₂·2H₂O, oxygen, perylene, ferrocene, bis(biphenyl)chromium(I) tetraphenylborate and tris(tetrabutylammonium) hexacyanoferrate in hexamethylthiophosphoric triamide.