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The theory of electronically nonresonant coherent Raman scattering (CRS) with quasi-cw noisy light (I(2) CRS) is developed for a general material response. The (Raman) resonant–resonant and resonant–nonresonant hyperpolarizability contributions to the I(2) CRS signal are interferometrically separable. It is found that, in general, the interferometric decay of each of these terms exposes the Raman line shape function in a different manner. Only for a Lorentzian line is their decay identical. Thus, in principle, I(2) CRS provides a new way to explore the line shape function that is analytically distinct from frequency domain and time domain methods. By way of illustration, the general theory is applied to three common line shapes: Lorentzian (as in the original I(2) CRS theory), Gaussian, and Voigt. The results are shown to be consistent with the principles of factorized time correlation diagram analysis.

For the first time, the high-frequency symmetric C−H stretching modes of chloroform and benzene are down-converted using the recently developed time−frequency-resolved interferometric coherent anti-Stokes Raman scattering with broad-band nontransform limited (noisy) light excitation method. As an application, chloroform−carbon tetrachloride, benzene−benzene-d6 and benzene−acetone-d6 dilution series are performed. Concentration-dependent Raman frequencies and vibrational dephasing rate constants are observed by this new technique.

Transient absorption spectroscopy has been used to elucidate the UV-A induced photodynamics of quinacrine. Following excitation of quinacrine in a pH 7.2 buffer solution at 395 nm, the excited molecule ejects an electron into the surrounding aqueous solution. The quantum efficiency for solvated electron formation at this excitation wavelength is determined to be in the range of 0.20−0.40. These results provide a simple mechanism that accounts for the generation of superoxide (O2 -) following UV excitation of quinacrine in aqueous solution.

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