Electrodeposition and properties of TEMPO functionalized polythiophene thin films

The modification of an azide-functionalized regioregular polythiophene with TEMPO groups is reported. The TEMPO functionalized polymer is characterized by ESR, ATR-IR, absorption and emission spectroscopies and electrochemical methods. Partial quenching of the polymer emission by the TEMPO groups is observed. The polymer may be electrodeposited onto ITO or carbon electrodes to give thin films. Cyclic voltammetry gives specific charge capacity values of 2.3 mA h g(-1) for the TEMPO functionalized polymers, and specific capacitances of 0.8 F g(-1) determined by galvanostatic charge/discharge experiments. The reduced charge capacity relative to unfunctionalized polythiophene is attributed to TEMPO induced cleavage and oxidation of the conjugated backbone.