A Hole Delocalization Strategy: Photoinduced Mixed-Valence MLCT States Featuring Extended Lifetimes

ARAMBURU-TRO?ELJ, BRUNO M.; OVIEDO, PAOLA S.; PIESLINGER, GERMAN E.; HODAK, JOSÉ H.; BARALDO, LUIS M.; GULDI, DIRK M.; CADRANEL, ALEJANDRO

INORGANIC CHEMISTRY

AMER CHEMICAL SOC

Año: 2019

0020-1669

Bimetallic trans-[RuII(tpm)(bpy)(μNC)-RuII(L)4(CN)]2+, where bpy is 2,2′-bipyridine, tpm is tris(1-pyrazolyl)methane and L = 4-methoxypyridine (MeOpy) orpyridine (py), was examined using ultrafast vis-NIR transientabsorption spectroscopy. Of great relevance are the longest-lived excited states in the form of strongly coupledphotoinduced mixed-valence systems, which exhibit intensephotoinduced absorptions in the NIR and are freely tunableby the judicious choice of the coordination spheres of themetallic ions. Using the latter strategy, we succeeded intailoring the excited state lifetimes of bimetallic complexesand, in turn, achieving significantly longer values relative torelated monometallic complexes. Notable is the success inextending the lifetimes, when considering the higher density of vibrational states, as they are expected to facilitate nonradiative ground-state recovery.