A photochemical metallocene route to anionic enediynes: synthesis, solid-state structures, and ab initio computations on cyclopentadienidoenediynes.

The first demonstration of photochemical enediyne liberation from a metal complex has led to a new class of enediynes, the cyclopentadienidoenediynes, which are demonstrated to exist as air-stable solids with low ionization potentials and large dipole moments. NMR and IR spectroscopy, X-ray crystallography, and ab initio computations enable a comparison with the ubiquitous benzoenediynes.