• Corpus ID: 118768567

Ultrafast Electron Dynamics Theory of Photo-excited Ruthenium Complexes

@article{Chang2010UltrafastED,
  title={Ultrafast Electron Dynamics Theory of Photo-excited Ruthenium Complexes},
  author={Jun Chang and Arthur J. Fedro and Michel Van Veenendaal},
  journal={arXiv: Strongly Correlated Electrons},
  year={2010}
}

• Jun Chang, A. Fedro, M. Veenendaal
• Published 24 March 2010
• Physics, Chemistry
• arXiv: Strongly Correlated Electrons

An explanation is provided for the ultrafast photo-excited electron dynamics in low-spin Ruthenium (II) organic complexes. The experimentally-observed singlet to triplet decay in the metal-to-ligand charge-transfer (MLCT) states contradicts the expectation that the system should oscillate between the singlet and triplet states in the presence of a large spin-orbit coupling and the absence of a significance change in metal-ligand bond length. This dilemma is solved with a novel quantum decay mechanism that causes a singlet to triplet decay in about 300 femtoseconds. The decay is mediated by the triplet metal-centered state ($^3$MC) state even though there is no direct coupling between the $^1$MLCT and $^3$MC states. The coupling between the $^3$MLCT and $^3$MC via excited phonon states leads to vibrational cooling that allows the local system to dissipate the excess energy. In the relaxed state, the population of the $^3$MC state is low and the metal-ligand bond length is almost unchanged with respect to the initial photoexcited state, in agreement with experiment.