Recently, our group cooperated with the group of Prof. Wenjing Hong, revealed that the delocalization of metalla-aromatics could be used to switch the charge transport pathway of single-molecule junctions.
    To explore the charge transport through metalla-aromatics building blocks, three metallacycles complexes were synthesized, and their single-molecule conductances were characterized by using mechanically controllable break junction technique. It is found that the conductance of the metallacycles junction with phosphonium group is more than 1 order of magnitude higher than that without phosphonium group. X-ray diffraction and UV–vis absorption spectroscopy suggested that the attached phosphonium group makes metallacycles more delocalized, which shortened the preferred charge transport pathway and significantly enhanced the single-molecule conductance. This work revealed that the delocalization of metalla-aromatics could be used to switch the charge transport pathway of single-molecule junctions and thus tune the charge transport abilities significantly.

    URL link for article: http://pubs.acs.org/doi/10.1021/jacs.7b06400