Carboxylic‐functionalized water soluble π‐conjugated polymer: Highly selective and efficient chemosensor for mercury(II) ions |
| |
Authors: | A. Balamurugan M. L. P. Reddy M. Jayakannan |
| |
Affiliation: | 1. Chemical Sciences & Technology Division, National Institute for Interdisciplinary Science and Technology, Thiruvananthapuram 695019, Kerala, India;2. Department of Chemistry, Indian Institute of Science Education and Research (IISER), NCL Innovation Park, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India |
| |
Abstract: | Here, we report a new carboxylic‐functionalized water soluble π‐conjugated polymer for selective detection of highly toxic Hg2+ in neutral pH condition. carboxylic‐functionalized thiophene containing oligophenylenevinylene was synthesized and polymerized under oxidative route to obtain water soluble polymer. Free carboxylic groups present in the π‐conjugated materials provide opportunity to use pH as external stimuli for studying secondary interaction such as hydrogen bonding and aromatic π‐stacking of the chromophores. The pH changes strongly influence on the molecular interactions in the monomer, whereas the long chain polymer was less disturbed. The polymer showed high selectivity for detecting Hg2+ ions compared with any other transition metal ions in water. The detection efficiency of the polymer was found almost 40 times higher than that of its monomeric unit. Stern‐Volmer constant for the Hg2+ ion sensing was determined through concentration dependent studies as 6.4 × 105 M?1. The carboxylic‐functionalized polymer showed reversibility in the metal‐ion detecting capabilities which was further investigated by NaCl complexation with Hg2+ complex. Both funneling of excitation energy to the Hg2+ center and also excitation energy migration through chain π‐conjugated backbone were correlated to the superior sensing characteristics of the polymer compared to its monomeric counterpart. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5144–5157, 2009 |
| |
Keywords: | conjugated polymer pH sensitive photophysical studies sensing synthesis water soluble |
|
|