Quantum chemical analysis and molecular dynamics simulations to study the impact of electron-deficient substituents on electronic behavior of small molecule acceptors

In present study, a multiscale computational analysis is performed to understand the impact of structural modification through electron-deficient group substitution on the electronic and molecular behavior of small molecule acceptors. Charge distribution of small molecule acceptors has significantly changed on the variation of number and strength of electron-deficient substituents. This led to electrostatic potential difference between different parts of molecules. Impact of electrostatic interactions on the exciton binding energy is also studied. With the increase of strength of terminal electron-deficient group, transition dipole moment has significantly increased and exciton binding decreased. Small molecule acceptors with more electron-deficient atom or groups will show faster charge transfer. Radial distribution function analysis has indicated increased intermolecular interactions with the increase of electron-deficient character on peripheries of molecules. The cyanated small molecule acceptors are promising candidate for organic solar cells.