Effect of heteroatoms substitution on electronic, photophysical and charge transfer properties of naphtha [2,1-b:6,5-b′] difuran analogues by density functional theory

Heteroatoms substitution technique was used and nitrogen (N) and sulpher (S) were doped to design new analogues of naphtha [2,1-b:6,5-b′] difuran (DPNDF) by replacing carbon (C) and hydrogen (H) atoms. The molecular structures of all analogues have been optimized at the ground (S0) and first excited (S1) states using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), respectively. Then highest occupied molecular orbitals (HOMOs), the lowest unoccupied molecular orbitals (LUMOs), photophysical properties, adiabatic/vertical electron affinities (EAa)/(EAv), adiabatic/vertical ionization potentials (IPa)/(IPv) and hole/electron reorganization energies λh/λe have been investigated. The effect of doping has been studied on the transfer integral, mobility and photostability. The photostability enhanced by increasing the number of nitrogen atoms. We obtained the high hole mobility as 0.96 cm2 V−1 s−1 for analogue “a”. The reorganization energies, transfer integrals and mobilities revealed that the “b” would be electron transporter, “d” balance hole as well as electron transporter, whereas the “a”, “c” and “e” may be good hole transport materials.