Abstract
In this topics, we overview the recent research trends on the photophysical properties of ruthenium(II) and rhenium(I) complexes having arylborane charge transfer unit(s). The vacant p-orbital on the boron atom (p(B)) in a triarylborane derivative plays important roles in determining the electronic structure and the excited-state properties of the derivative. Recent studies on the spectroscopic and excited-state properties of arylborane compounds indicated that the characteristic absorption and fluorescence bands were ascribed essentially to the charge transfer (CT) transition between the π-orbital of the aryl group (π(aryl)) and p(B) : π(aryl)-p(B) CT. By utilizing such characteristics of triarylborane derivatives, new approaches toward tuning of the redox, spectroscopic, and excited-state properties of transition metal complexes have been explored through combining the π(aryl)-p(B) CT interaction in a triarylborane derivative with the metal-to-ligand charge transfer (MLCT) state of a transition metal complex.
