Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Systems containing univalent copper, phosphineacetic acid H_nL with the general formula Ph_3-nP(CH₂COOH)_n (n = 1-3) and acetonitrile in a concentration necessary for stabilizing free copper(I) were studied by potentiometry with copper amalgam and glass indicating electrodes. The measurements were carried out in water and in 50 v/v % dioxan at 25 °C and I = 0.1 (NaClO₄). Consecutive formation of complexes with Cu^I : L^n- = 1 : 1, 1 : 2, 1 : 3 and 1 : 4, whose stability decreases slightly with an increasing number of acetate groups in the ligand and from 50% dioxan to water, was found in all systems. In these complexes the ligands are coordinated through the phosphorus atom alone. The acetonitrile completes the coordination sphere of copper in complexes with L/Cu < 4.