Symmetrically and unsymmetrically 2,5-difunctionalizedphospholes bearing ester groups were prepared in a one-potprocedure from the corresponding diynes and dichloro(phenyl)phosphine via titanacyclopentadienes. The observedoptical properties of the functionalized phospholes show thatthe π-conjugative push−pull interaction between the 2- and5-substituents plays an important role in controlling the light-emitting efficiency.
