Excited-state structure by time-resolved X-ray diffraction.
X-ray crystallography has traditionally been limited to the study of the ground-state structure of molecules and solids. Recent technical advances are removing this limitation as demonstrated here by a time-resolved stroboscopic study of the photo-induced 50 micros lifetime excited triplet state of the [Pt(2)(pop)(4)](4-)ion [pop = pyrophosphate, (H(2)P(2)O(5))(2-)], performed at helium temperatures with synchrotron radiation. The shortening of the Pt-Pt bond by 0.28(9)A upon excitation is compatible with the proposed mechanism involving promotion of a Pt-Pt antibonding dsigma* electron to a weakly bonding p orbital. The contraction is accompanied by a 3 degree molecular rotation. The time-resolved diffraction technique described here is applicable to reversible light-driven processes in the crystalline solid state.
Kim
Christopher D
CD
Department of Chemistry, State University of New York at Buffalo, Buffalo, NY 14260-3000, USA.
Pillet
Sebastien
S
Wu
Guang
G
Fullagar
Wilfred K
WK
Coppens
Philip
P