Inverse Design of Conjugated Polymers from Computed Electronic Structure Properties: Model Chemistries of Polythiophenes

Abstract

Using a diverse set of 100 oligothiophenes, extrapolated oligomer and polymer HOMO, LUMO and HOMO-LUMO gaps are shown to be accurately estimated from the computed values of the trimer HOMO, trimer LUMO and trimer HOMO-LUMO gaps. These simple approximations can be improved further through easy to calculate properties of monomers or small oligomers. Polymer reorganization energies, related to the hole transport, are also shown to be predicted accurately from small oligomers. Correlations between the HOMO slope with the HOMO polymer energy and HOMO-LUMO gap slope with the polymer HOMO-LUMO gap energy suggest that the degree of delocalization reflected in the slope is higher in monomers and polymers with electron-rich, less negative HOMO eigenvalues. These statistical models can serve as efficient screens for the computational prediction of polythiophene properties.