Visible-light photolysis of [FeCp(η6-toluene)][PF6] as a clean, convenient and general route to iron-vinylidene and iron-acetylide complexes

Visible-light photolysis of the cheap starting material [FeCp(η6-toluene)][PF6] (Cpdouble bond; length as m-dashη5-C5H5) using a simple 100-W globe in the presence of diphenyldiphosphinoethane (dppe) and terminal alkynes cleanly yields the vinylidene complexes [FeCp(dppe)(double bond; length as m-dashCdouble bond; length as m-dashCHR)][PF6] and, upon further deprotonation, the iron-alkynyl complexes; the reaction is extended to ferrocenylacetylene to yield a bimetallic complex.