3MLCT excited states in Ru(II) complexes:: Reactivity and related two-photon absorption applications in the near-infrared spectral range

This short review provides a concise summary of the current state of research on the population by two-photon absorption of the triplet metal-to-ligand (MLCT)-M-3 excited state of ruthenium(II) complexes. Several effective and potential applications of this non-linear optics phenomenon (optical power limiting in the near infrared, biological imagery and photodynamic therapy, PDT) and related linear effects will also be presented.