Antiaromatic compounds have generated a lot of interest in the field of molecular electronics over recent years. They typically display low HOMO-LUMO gaps, which has been envisaged to yield high electrical conductance. In this work, a team led by L. A. Zotti at IFIMAC in collaboration with E. Leary at IMDEA Nanociencia have studied molecular wires incorporating dithienopentalenes. They found that the final result is ruled by a delicate interplay between the expected reduction of the HOMO-LUMO gap and the appearance of destructive quantum interference, which are in turn affected by the position of the heteroatom within the junction. Strikingly, they also found that the graphical “curly-arrow” rules, commonly used to predict the appearance of destructive interference, fail for certain isomers, regardless of the degree of antiaromaticity. [Full article]
