Theoretical and modelling investigation of pendant groups effect on quantum interference for single-molecule junctions.

Quantum interference (QI) is one of the most important phenomena that affects the charge transport through single molecules. The effect of a constructive and destructive quantum interference on electronic, thermoelectric and spectroscopic properties of oligo(phenyleneethynylene) based-molecular junctions has been investigated using a combination of density functional theory (DFT) methods, tight binding (Hückel) modelling (TBHM) and quantum transport theory (QTT). Molecules with carbonyl, diphenyl, ethane and ethynylferrocene substituents show a destructive quantum interference (DQI), which enhances thermoelectric properties of these molecules making them promising materials for thermoelectric applications.