Vibrational Dynamics and Heat Capacity of Poly(3-methylthiophene): A Conducting Polymer

Abstract

Using the Urey–Bradley force field and Wilson's GF matrix method as modified by Higgs, normal modes of vibration and their dispersions in poly(3-methylthiophene) have been obtained. They provide a detailed interpretation of its I.R. and Raman spectra. Characteristic features of the dispersion curves, such as regions of high density-of-states, repulsion, and character mixing of dispersive modes, are discussed. Predictive values of the heat capacity as a function of temperature have been calculated.

Keywords:

• density-of-states
• heat capacity
• infrared
• phonon dispersion
• poly(3-methylthiophene)
• Raman spectroscopy