Two-dimensional Raman spectroscopy

Time-resolved spectroscopy has become an important field from x-rays to the far-IR. Both IR and Raman spectroscopies have been adapted to time-resolved studies. There have been a large number of studies using time-resolved Raman [39], time-resolved resonance Raman [7] and higher order two-dimensional Raman spectroscopy (which can provide coupling infonuation analogous to two-dimensional NMR studies) [40]. Time-resolved IR has probed neutrals and ions in solution [41, 42], gas phase kmetics [42] and vibrational dynamics of molecules chemisorbed and physisorbed to surfaces [44]- Since vibrational frequencies are very sensitive to the chemical enviromnent, pump-probe studies with IR probe pulses allow stmctiiral changes to... 

Tokmakoff A, Lang M J, Larsen D S, Fleming G R, Chernyak V and Mukamel S 1997 Two-dimensional Raman spectroscopy of vibrational interactions in liquids Phys. Rev. Lett. 79 2702-5... 

Tokmakoff A and Fleming G R 1997 Two-dimensional Raman spectroscopy of the intermolecular modes of liquid CSj J. Chem. Phys. 106 2569-82... 

Tokmakoff A, Lang M J, Jordanides X J and Fleming G R 1998 The intermolecular interaction mechanisms in liquid CS2 at 295 and 165 K probed with two-dimensional Raman spectroscopy Chem. Phys. 233 231-42... 

Femtosecond liquid dynamics studied by two-dimensional Raman spectroscopy... 

Fifth-Order Two-Dimensional Raman Spectroscopy of the Intermolecular and Vibrational Dynamics in Liquids... 

We first consider the intermolecular modes of liquid CS2. One of the details that two-dimensional Raman spectroscopy has the potential to reveal is the coupling between intermolecular motions on different time scales. We start with the one-dimensional Raman spectrum. The best linear spectra are based on time domain third-order Raman data, and these spectra demonstrate the existence of three dynamic time scales in the intermolecular response. In Fig. 3 we have modeled the one-dimensional time domain spectrum of CS2 for 3 cases (A) a single mode represented by the sum of three Brownian oscillators, (B) three Brownian oscillators, and (C) a distribution of 20 arbitrary Brownian oscillators. Case (A) represents the fully coupled, or isotropic case where the liquid is completely homogeneous on the time scales of the simulation. Case (B) deconvolutes the linear response into the three time scales that are directly evident in the measured response and is in the limit that the motions associated with each of the three timescales are uncoupled. Case (C) is an example where the liquid is represented by a large distribution of uncoupled motions. 

In this chapter we have demonstrated the great promise of two-dimensional Raman spectroscopy to go beyond the ensemble average of linear spectroscopy and reveal the microscopic details that underlie the vibrational... 

Saito, S., Ohmine, I. (2002). Off-resonant fifth-order response function for two-dimensional Raman spectroscopy of liquids CS2 and H2O. Phys. Rev. Lett. 88 207401(1 ). 

Kubarych, K.J., Milne, C.J., Miller, R.J.D. (2003). Fifth-order two-dimensional Raman spectroscopy A new direct probe of the liquid state. Int. Rev. Phys. Chem. 22 497-532. 

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