Time-resolved Laue diffraction of excited species at atomic resolution: 100 ps single-pulse diffraction of the excited state of the organometallic complex Rh-2(mu-PNP)(2)(PNP)(2)center dot BPh4

The polychromatic Laue technique has been applied in 100 ps delay synchrotron pump-probe experiments of the triplet excited state of a Rh(I) dinuclear complex. The observed contraction of the Rh-Rh distance of 0.154 (13) angstrom is less than predicted by a series of theoretical calculations, a difference attributed to the constraining effect of the crystal lattice.