title: Filming the birth of molecules and accompanying solvent rearrangement.
abstract: Molecules are often born with high energy and large-amplitude vibrations. In solution, a newly formed molecule cools down by transferring energy to the surrounding solvent molecules. The progression of the molecular and solute-solvent cage structure during this fundamental process has been elusive, and spectroscopic data generally do not provide such structural information. Here, we use picosecond X-ray liquidography (solution scattering) to visualize time-dependent structural changes associated with the vibrational relaxation of I(2) molecules in two different solvents, CCl(4) and cyclohexane. The birth and vibrational relaxation of I(2) molecules and the associated rearrangement of solvent molecules are mapped out in the form of a temporally varying interatomic distance distribution. The I-I distance increases up to ~4 Å and returns to the equilibrium distance (2.67 Å) in the ground state, and the first solvation cage expands by ~1.5 Å along the I-I axis and then shrinks back accompanying the structural change of the I(2) molecule.
authors: Center for Time-Resolved Diffraction, Department of Chemistry, KAIST, Daejeon 305-701, Republic of Korea.
authors: Jae Hyuk
authors: JH
authors: Lee
authors: Michael
authors: M
authors: Wulff
authors: Savo
authors: S
authors: Bratos
authors: Jakob
authors: J
authors: Petersen
authors: Laurent
authors: L
authors: Guerin
authors: Jean-Claude
authors: JC
authors: Leicknam
authors: Marco
authors: M
authors: Cammarata
authors: Qingyu
authors: Q
authors: Kong
authors: Jeongho
authors: J
authors: Kim
authors: Klaus B
authors: KB
authors: Møller
authors: Hyotcherl
authors: H
authors: Ihee