Phenylene as an efficient mediator for intermetallic electronic coupling.

The new compound [(NC)Ru 2 (ap) 4 ] 2 (μ-1,4-C 6 H 4 ) (ap = 2-anilinopyridinate) was prepared to address the open question of whether a 1,4-phenylene bridge can mediate intermetallic electronic coupling. As a manifestation of strong coupling, hole delocalization between the Ru 2 centers on the IR time scale (10 -14 s) was established using spectroelectrochemistry. An orbital mechanism for coupling was elaborated with DFT analysis.