Conducting polymer and metal–complex composites formed by complexation of the ligands from the vapour phase

Abstract

Complexation from the vapor phase is, for the first time, used to coordinate ligands to metal ion(s) inside a conducting polymer matrix.This new class of composites was examined with regard to different ligands and metal ions. The reduction reaction of nitrite to ammonia was used as a case study for the functionality of the composites.Vapour phase polymerisation (VPP) of conducting polymers (CPs) has been a research topic for many years. 1-6 The obtained polymers have been used for various applications e.g. microfabrication, biomedical purposes, membranes, nanoparticle composites and sensors, 4-7 and for various catalytic reactions e.g. oxygen reduction 3 and water oxidation. 8 Functionalisation by incorporation of molecules such as enzymes, redox species as well as metallic species has further broadened the use of the CPs. 7,9,10 CP metal composites have been researched extensively and can be used for catalysts, 9 sensors, 11,12 supercapacitors, 13 and in biomedical applications. 14 Various methods have been used to form the composites by either physical entrapment, 15 covalently bonding, 16 templating, 17 self-assembly, 18 chemical reduction 12,19 or electrochemical polymerisation. 14 In general, the CP metal composites as such were formed using solution-based techniques. 9,[11][12][13][14][15][16][17][18][19] The concept of using ligand to coordinate metal with the polymeric network has been commonly used by the research for the metal and organic composites so called metal-organic hybrid coordination polymers those obtained from various preparation methods which are all solution-based. 17,18,[20][21][22][23][24][25][26] In those works, the metal ions were coordinated directly with the ligands which are non-conducting molecules/polymers.The difficulty in preparing the composites of conducting polymers and ligand-metal complexes is not only the poor solubility of many ligand-metal complexes but also that, to form ; Fax: +61 3 9905 4940; Tel: +61 3 9905 5343 † Electronic supplementary information (ESI) available: Materials and cyclic voltammetry. See