A very large Rh-Rh bond shortening on excitation of the [Rh-2(1,8-diisocyano-p-menthane)(4)](2+) ion by time-resolved synchrotron X-ray diffraction

A very large Rh - Rh contraction of similar to0.85 Angstrom occurs on excitation of the [Rh-2(1,8-diisocyano-p-menthane)(4)](2+) ion to its triplet state.