Quantum-Interference and Spin-Selectivity in Diboracene-Based Nanojunctions

New designs for molecular switches are essential for driving the development of nanoelectronics. The effect of quantum interference in cross-conjugated structures such as anthracene have already been thoroughly explored. A similar structural motif can be found in diboracenes, whose unsubstituted variants could only be synthesized recently. In this contribution, we explore the potential of these structures to produce similar quantum interference effects varying with substitution and how these could be used to produce a spin-filtering device. We investigate the eletronic properties of diboracenes through density functional theory and the global and local transport properties at the quasi-stationary limit using nonequilibrium Green’s function methods. Our findings show how the current may be tuned through the substituent and that larger unsubstituted diboracenes favor a triplet ground state with a destructive quantum interference effect for one of the spin channels.