An investigation of modified AgI solid electrodes containing the homopiperazinium cation—I. Synthesis and characterization

Abstract

Homopiperazinium and N, N, N′, N′-tetramethylhomopiperazinium diiodide (briefly designated as HI 2 and TMHI 2) have been synthesized and characterized by infrared spectroscopy and proton magnetic resonance spectroscopy. The two diazonia diiodides were reacted with silver iodide in concentrations ranging from 75 to 95 equivalent I − of AgI. In both HI 2-AgI and TMHI 2-AgI systems, the study of the total electrical conductivity with respect to temperature shows that the Arrhenius equation is obeyed. At 25°C, the maximal conductivity is reached for an equivalent content of 85% in the HI 2-AgI system with a value of 0.003 (ohm cm) −1. For the TMHI 2-AgI system a dissymetric composition dependence of the electrical conductivity is observed around a main maximum at 90% AgI content corresponding to a 0.027 (ohm cm) −1 conductivity. Existence in this system of a second electrolyte phase around a 77.5–80% composition in AgI is sustained by electrochemical conductivity measurements and an independent X-ray powder diffraction study.