Structure and Color of Pentaphenylbismuth

A violet color and strong dichroism are very unusual features for a compound of a main‐group element. The X‐ray structure analysis performed at −96°C reveals that Bi(C 6 H 5 ) 5 , synthesized earlier by Wittig et al., may be described as a square pyramid and is thus very similar to the (colorless!) Sb(C 6 H 5 ) 5 . Optical investigations showed that excitation occurs in the basal plane of the square pyramid. A charge‐transfer transition from a ligand to the bismuth atom was proposed.