Study of a new crown-ether derivatized polydioxypyrrole

A new fused tetramethyl substituted 14-crown-4 3,4-pyrrole (TMC-DOP) has been polymerized and the redox switching properties of the resultant polymer investigated such as its possibility of lithium ion sensing. Especially, interesting redox properties have been obtained when the polymerization is carried out galvanostatically at a low current density of less than 50 μA cm−2. In this instance, two redox processes labeled α (E0∼−0.65 V) and β (E0∼+0.15 V) are reproducibly observed. A cation sensing study revealed a clear cyclic voltammetric response due to a β→α process conversion with a slightly higher sensitivity for lithium ions when compared to sodium ions. The poly(TMC-DOP) exhibited a strong electrochromic response, changing from yellow at −0.7 V to highly transmissive and color neutral at +0.2 V indicating possible ionochromic behavior upon optimization of the electrochemical detection load.