Tokyo Institute of Technology research: Antiaromatic molecule displays record electrical conductance

Researchers demonstrate high electrical conductance for an antiaromatic nickel complex - an order of magnitude higher than for a similar aromatic complex. Since the conductance is also tunable by electrochemical gating, antiaromatic complexes are promising materials for future electronic devices. Organic materials often have a lower production cost than traditional electric conductors like metals and semiconductors. Not all organic systems conduct electricity well, however. A class of organic materials known as antiaromatic compounds - featuring planar rings of carbon atoms sharing a number of electrons that is a multiple of 4 - have been predicted to be excellent conductors, but this prediction has been hard to verify since antiaromatic molecules are usually unstable. Now, Shintaro Fujii and Manabu Kiguchi from the Tokyo Institute of Technology and colleagues have performed a systematic study of charge transport in a single, stable antiaromatic molecule. Compared to a structurally related aromatic molecule (where the carbon rings share an extra two electrons), its record electrical conductance is an order of magnitude higher. The researchers studied a particular norcorrole-based nickel complex, Ni(nor), which is antiaromatic but stable, and a structurally similar aromatic, porphyrin-based nickel complex, Ni(porph). They measured the conductivities of the two comp...