Tracking Intramolecular Vibrational Redistribution in Polyatomic Small-Molecule Liquids by Ultrafast Time–Frequency-Resolved CARS

Abstract

Selective excitation of C-H stretching vibrational modes, detection of intramolecular vibrational energy redistribution (IVR), and vibrational modes coupling in the electronic ground state of benzene are performed by using femtosecond time- and frequency-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy. Both of the parent modes in the Raman-active bands are coherently excited by an ultrafast stimulated Raman pump, giving initial excitations of 3056 cm (A) and 3074 cm (E) and subsequent IVR from the parent modes to daughter modes of 1181 and 992 cm, and the coherent vibrational coupling of the relevant modes is tracked. The directionality and selectivity of IVR and coherent coupling among all of the relevant vibrational modes are discussed in the view of molecular symmetry.

Tracking intramolecular energy redistribution dynamics in aryl halides: the effect of halide mass

“…[9][10][11][12] Analysis of mono-substituted benzenes reveals that the inuence of a single group will be essential. 11,12 Monosubstituted benzenes are chosen for this study because of our prior knowledge of benzene's intramolecular energy redistribution, 13 and we can describe a series of molecules where the basic phenyl structure remains unchanged. According to our previous work, 13 isolated-molecule energy ow of benzene was described, so the vibrational energy redistribution observed in liquid aryl halides X-Ph (X ¼ F, Cl, Br, I; -Ph ¼ C 6 H 5 ) is entirely a consequence of intramolecular interactions.…”

“…11,12 Monosubstituted benzenes are chosen for this study because of our prior knowledge of benzene's intramolecular energy redistribution, 13 and we can describe a series of molecules where the basic phenyl structure remains unchanged. According to our previous work, 13 isolated-molecule energy ow of benzene was described, so the vibrational energy redistribution observed in liquid aryl halides X-Ph (X ¼ F, Cl, Br, I; -Ph ¼ C 6 H 5 ) is entirely a consequence of intramolecular interactions. Using the narrow band CARS technique, it is easy to understand the effect of substituent mass on vibrational energy redistribution.…”

Role of electron in intramolecular vibrational energy redistribution: a simulation of time- and frequency-resolved CARS spectrum

“…It should be mentioned that only three couplings between vibrational modes are set to be nonzero, which are adopted corresponding to the conjecture in ref. 9. The physical meanings of these coupling strengths will be discussed in the Discussion section.…”

“…The simulation parameters are set according to the experimental results in ref. 9. In this previous experimental work, ve fundamental modes, labelled as n 1-5 , have been identied participating in the IVR process.…”

Molecular Dynamics and Energy Transfer in Pure Aniline and Rh101+/Aniline Mixed Solution Measured by Ultrafast Spectroscopy

“…Another reason for choosing aniline in our study is that many articles have report electron transfer of Rh101 + /aniline in the electronic excited state, but little attention has been paid to study the dynamics processes in the electronic ground state. [13][14][15][16] In our manuscript, vibrational dynamics happen in in the electronic ground state, and we have described vibrational energy transfer before chemical reaction. In our work, we study the effect of hydrogen bonds on vibrational dynamics and energy transfer processes before degradation.…”