1,4,8,11-Tetrakis(4-ferrocenyl-3-azabutyl)-1,4,8,11-tetraazacyclotetradecane as a ferrocene-functionalised polyammonium receptor for electrochemical anion sensing

Abstract

The interaction of the ferrocene-functionalised polyaza receptor 1,4,8,11-tetrakis(4-ferrocenyl-3-azabutyl)-1,4,8,11-tetraazacyclotetradecane (L¹) with sulfate, phosphate and ATP has been studied potentiometrically in THF–water 70∶30 v/v (0.1 mol dm^–3 tetrabutylammonium perchlorate, 25 °C). The molecular structure of the free receptor has been determined by single-crystal X-ray procedures. An electrochemical study on L¹ as a function of the pH has been carried out in THF–water 70∶30 v/v in the presence of the sulfate, phosphate and ATP anions. The potential use of L¹ as an anion sensing receptor is discussed in terms of the electrochemical and potentiometric data and its behaviour is compared with those of related redox-active polyammonium receptors.