A DFT approach to analyze charge transfer path through trans and cis isomers of azobenzene

Abstract

The influence of external electrical field (EF) over the trans and cis isomers of azobenzene is investigated upto molecular orbital level with the aid of density functional theory. The frontier molecular orbital analysis and electrostatic potential (ESP) mapping are used to figure out the response of the molecules (trans and cis isomers of azobenzene) to the applied EF. The variation in dipole moment gives the extent of polarization in the molecule due to EF. With the aid of natural bond orbital analysis (NBO) the possible charge transfer path through the molecule can be predicted. ESP and NBO analysis clearly shows that drastic charge redistribution takes place for the EF strength of 0.15 V/Å. Hence the EF strength above 0.15 V/Å can be considered as threshold filed strength for organic molecular conductance. All these theoretical investigations provide a basic knowledge about the influence of molecular conformation over the conductivity of a molecule in the presence of EF.