Charge transfer in strongly correlated systems: an exact diagonalization approach to model Hamiltonians.
We study charge transfer in bridged di- and triruthenium complexes from a theoretical and computational point of view. Ab initio computations are interpreted from the perspective of a simple empirical Hamiltonian, a chemically specific Mott-Hubbard model of the complexes' π electron systems. This Hamiltonian is coupled to classical harmonic oscillators mimicking a polarizable dielectric environment. The model can be solved without further approximations in a valence bond picture using the method of exact diagonalization and permits the computation of charge transfer reaction rates in the framework of Marcus' theory. In comparison to the exact solution, the Hartree-Fock mean field theory overestimates both the activation barrier and the magnitude of charge-transfer excitations significantly. For triruthenium complexes, we are able to directly access the interruthenium antiferromagnetic coupling strengths.
Institut für Physikalische Chemie, Universität Freiburg, Albertstraße 23a, D-79104 Freiburg im Breisgau, Germany.
Andreas
A
Schöppach
Institut für Physikalische Chemie, Universität Freiburg, Albertstraße 23a, D-79104 Freiburg im Breisgau, Germany.
David
D
Gnandt
Institut für Physikalische Chemie, Universität Freiburg, Albertstraße 23a, D-79104 Freiburg im Breisgau, Germany.
Thorsten
T
Koslowski
D003198:Computer Simulation; D056831:Coordination Complexes / Q000737:chemistry*; D004583:Electrons; D008956:Models, Chemical; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry*
D056831:Coordination Complexes; D012428:Ruthenium