Homoleptic and Heteroleptic Ruthenium(II) Complexes Based on 2,6-Bis(quinolin-2-yl)pyridine Ligands - Multiple-Charged-State Modules for Potential Density Memory Storage

摘要

The two ligands 2,6-bis(4-methylquinolin-2-yl)pyridine (L-1) and diethyl 2,2-(pyridine-2,6-diyl)bis(quinolone-4-carboxylate) (L-2) were used to prepare the homoleptic [Ru(L-2)(2)][PF6](2) (RU1) and heteroleptic [Ru(L-1)(L-2)][PF6](2) (RU2) complexes. DFT calculations (B3PW91,3-21G**) performed on both RU1 and RU2 revealed that redox at the ruthenium site for RU2 is less positive by ca. 110 mV. Consequently, the one-electron ligand-based reduction for RU2 is more cathodic by 80 mV. Electrochemistry experiments confirmed that the prediction is qualitatively correct and that the complexes can each hold up to five electrons reversibly.