Nonlinear optical studies on new conjugated poly{2,2l‐(3,4‐ dialkoxythiophene‐2,5‐diyl) bis[5‐(2‐thienyl)‐1,3,4‐oxadiazole]}s |
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| Authors: | Pramod Kumar Hegde A. Vasudeva Adhikari M. G. Manjunatha C. S. Suchand Sandeep Reji Philip |
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| Affiliation: | 1. Organic Chemistry Division, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India;2. Light and Matter Physics Group, Raman Research Institute, Bangalore 560080, India |
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| Abstract: | Three new donor–acceptor type poly{2,2l‐(3,4‐ dialkoxythiophene‐2,5‐diyl)bis[5‐(2‐thienyl)‐1,3,4‐oxadiazole]}s ( P1, P2, and P3 ) were synthesized starting from thiodiglycolic acid and diethyl oxalate through multistep reactions. The polymerization was carried out using chemical polymerization technique. The optical and charge‐transporting properties of the polymers were investigated by UV‐visible, fluorescence emission spectroscopic and cyclic voltammetric studies. The polymers showed bluish‐green fluorescence in solutions. The electrochemical band gaps were determined to be 2.03, 2.09, and 2.17 eV for P1 , P2, and P3, respectively. The nonlinear optical properties of new polymers were investigated at 532 nm using single beam Z‐scan and degenerate four‐wave mixing (DFWM) techniques with nanosecond laser pulses. The polymers exhibited strong optical limiting behavior due to “effective” three‐photon absorption. Values of the effective three‐photon absorption ( 3PA ) coefficients, third‐order nonlinear susceptibilities (χ(3)), and figures (F) of merit were calculated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 |
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| Keywords: | conjugated polymer synthesis 3,4‐dialkoxythiophene NLO 3PA |
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