A DENSITY-FUNCTIONAL STUDY OF THE MLCT STATES OF [RU(BPY)3]2+ IN D3 SYMMETRY

A density functional based first principles study of the metal to liga nd charge-transfer (MLCT) states of [Ru(bpy)3]2+ is presented. The met hod used in this study includes first-order electrostatic multiplet sp litting as well as spin-orbit interaction. The results obtained show t hat there is an important mixing of the excited singlet and triplet st ates. These first principles results are in good overall agreement wit h the observed absorption spectra, with respect to both the spread of the excitation energies and the positions of the strong, unambiguously assigned peaks. Our calculation finds the lowest excited states to be virtually degenerate A1 and E spin-orbit components of the (dpi:a1) - -> (pi:a2) 3A2 State, the former lying a few 10-cm-1 units below the latter one. The next excited triplet, i.e. (dpi:e) - (pi:a2) 3E, aris es only roughly 1500 cm-1 above the 3A2.