Triarylboranes show unique spectroscopic and photophysical properties owing to charge transfer (CT) from the pi orbital of the aryl group (pi(aryl)) to the vacant p orbital on the boron atom (p(B)): pi(aryl)-p(B) CT. In the case of a transition-metal complex, the metal-to-ligand CT excited state is influenced largely by the presence of a pi(aryl)-p(B) CT unit in the ligand. Characteristic properties of triarylboranes and transition-metal complexes having a pi(aryl)-p(B) CT unit are reported.