Facile synthesis of malachite green incorporated conducting polymers: A comparison of theoretical and experimental studies

Abstract

The present work reports studies of Malachite Green (MG) dye incorporated conducting polymers of aniline, 1-naphthylamine, carbazole and pyrrole synthesized via ultrasound-assisted in-situ polymerization. The synthesized polymers were characterized for their spectral and morphological properties. Scanning electron microscopy (SEM) studies revealed the formation of well-organized nanostructured morphology. X-ray diffraction (XRD) studies confirmed semi-crystalline morphology of the polymers. FTIR and 1H-NMR studies confirmed the incorporation of MG dye in the polymers and were found to be comparable to the theoretically predicted spectra. Theoretical IR and UV–vis calculations were carried out using DFT/B3LYP method with 6-311++ G(d,p) basis set while the 1H-NMR spectra were computed using the gauge independent atomic orbital (GIAO) method. The theoretically computed UV spectra as well as oscillator strength values were found to be closely matching with the experimentally observed spectra. Fluorescence studies revealed remarkable changes in the emission spectra upon incorporation of MG dye in the polymers exhibiting high quantum yield values. This method of dye incorporation was shown to be effective for tuning the band gap of conducting polymers which could be utilized for designing biosensing as well as bioimaging devices.