Tuning of through-bond electronic coupling by donor and acceptor substitutions in the [(NH 3) 5Ru—1,4-dicyanobenzene—Ru(NH 3) 5] 5+ complex

Abstract

Through-ligand electronic coupling in the [(NH 3) 5Ru III—1,4-dicyanobenzene—Ru II(NH 3) 5] 5+ complex is calculated depending on the donor or acceptor grafted on the benzene. The coupling strength is first discussed, showing that through-dicyanobutadiene is larger than through-1,4-dicyanobenzene coupling. With this ligand, the largest electronic coupling is reached with a full 4NO 2 substitution on the benzene. Coupling through an asymmetric 2NO 22NH 2-substituted benzene is one order of magnitude lower. This large difference is interpreted using the number and position of the active ligand molecular orbitals relative to the d-ruthenium orbital.