Real-time dynamics of clusters. I. I2Xn (n=1)

Abstract

Vibrational predissociation of I, X, (X = Ne, Ar) van der Waals clusters are studied in realtime using picosecond pump-probe (LIF) and molecular beam techniques. The state-to-state rates of vibrational predissociation are measured for specific vibrational levels v] by monitoring the rise of nascent I,. Here, we report our study of k(uj.uj) 1,X(&u;) + I, (B,vj) + x.For I, Ne, the values of r = k -' (v],z$) decrease nonlinearly from 2 16 ps for v] = 13 to 53 ps for vi = 23. For 1,Ar (B,vj), which undergo electronic and vibrational predissociation, the risetime of the nascent I, is found to be 70 ps when 0; = 18 and 77 ps when v] = 21. A number of theoretical models for vibrational predissociation (the energy-gap law, the momentum-gap law, quantum and classical calculations) are compared with our experimental results in an attempt to understand the key features of the dynamics and the potential energy surface.

Quantum-mechanical study of the I2–Ne vibrational predissociation dynamics: A three-dimensional time-dependent self-consistent-field approach

“…A large variety of chemical reactions have been investigated through timeresolved experiments, among them the photoinduced dissociation of weakly bound van der Waals ͑vdW͒ clusters. 3,5,7͑b͒ More specifically, real-time techniques have been applied in recent years to explore the vibrational predissociation ͑VP͒ of vdW systems, 5 which was extensively studied in the past by means of frequency-domain spectroscopic experiments. [11][12][13] The increasing availability of experimental data in the time domain has stimulated the theoretical efforts in the direction of developing time-dependent methods to rationalize such information.…”

Femtosecond dynamics of solvated oxygen anions. I. Bifurcated electron transfer dynamics probed by photoelectron spectroscopy

“…These microscopic solvation processes, which may involve energy redistribution, electron transfer, and vibrational predissociation, have been examined in a variety of ionic [1][2][3][4][5][6][7][8][9] and neutral [10][11][12][13][14] clusters.…”

A three-dimensional wave packet study of Ar⋅ ⋅ ⋅I2(B )→Ar + I + I electronic predissociation

“…These complexes can be studied with the use of supersonic beams, and a large number of experimental and theoretical studies have been devoted to the study of the excitation and decay of van der Waals complexes involving I 2 . [10][11][12][13][14] When the van der Waals molecule M•••I 2 , where M is a rare gas atom or a molecule, is excited in the spectral region of the I 2 (B←X) transition, the fluorescence excitation spectrum shows broadened features which are attributed to quasibound levels associated to M Since channel 1 produces electronically excited I 2 fragments which can fluoresce while channel 2 is dark, measurements of the M•••I 2 absorption/I 2 fluorescence quantum yield ratio in conjunction with absorption spectra can provide the relative importance of vibrational and electronic predissociation. 13 For He•••I 2 and Ne•••I 2 , vibrational predissociation is much faster than electronic predissociation.…”