Polyfurans: A Computational Study
Polyfurans and furan-based polymers have recently emerged as a new class of conjugated materials. We undertook the first comprehensive computational study of polyfurans, especially doped polyfurans, and systematically compared their properties with those of the corresponding polythiophenes. Parent polyfuran has higher highest occupied crystal orbit and lowest unoccupied crystal orbit energies (by 0.25 and 0.61 eV, respectively), as well as a higher band gap (by 0.36 eV) and significantly larger twisting energy than that of polythiophenes. Doping of polyfuran and polythiophene was less exothermic than polyselenophene in all cases. For thermodynamic reasons, polyfurans should be easier to dope lightly than polythiophenes, whereas at heavy doping levels polyfurans and polythiophenes should be doped with similar ease.