Resonance Raman and optical dephasing study of tricarbocyanine dyes

Abstract

Fluorescence lineshape analysis based on resonance Raman spectra of the dye HITCI was used to determine the details and magnitude of the vibrational part of the line broadening function. Forced light scattering (FLS) was applied to measure optical dephasing of HITCI in ethylene glycol, pumping at 770 nm with 20 fs pulses from a Ti :sapphire laser and probing with continuous-wave light from an argon ion laser. The observed response is well described by the line broadening function derived from the Ñuorescence lineshape. High-frequency vibrational modes not covered directly by the laser spectrum account for 20% of the vibration-induced broadening in the FLS experiment. This e †ect is explained by di †erence frequency mixing with thermally populated low-frequency vibrations.

Wave Packet Dynamics in Ultrafast Spectroscopy of the Hydrated Electron

“…83,[85][86][87] Our previous experiments on dyes, however, showed this generally not to be the case. 8 Figure 4 shows that the spectral content of C(ω) agrees rather favorably with the unpolarized Raman spectrum of the highest frequency librational band of neat water 84,88,89 (note that the Raman spectrum of water in Figure 4 is multiplied by ω to allow a direct comparison with the spectral density 91 ). We note that a librational mode of similar frequency was found in model calculations on solvation dynamics in water by Hsu et al 12 We also note that the exponential part of our correlation function is identical to the one reported by Schwartz and Rossky.…”

Resonance Raman and Optical Dephasing Study of Hitci

“…Making the Condon approximation and assuming the low temperature limit, the vibrational contribution to the broadening of the absorption and fluorescence can be calculated (e.g. [3]). It is readily shown, that the spectral density p(co) is related to the resonance Raman spectrum IR(co) by…”

“…TFWM of HITCI (1,7-Bis-[1,3,3-trimethyl-3H-indol-2-yl]-heptamethinium iodide) in solution has recently been extensively studied (Refs. [2][3][4] and references therein). The resonance Raman spectrum, exciting at 627 nm, shown in Figure was obtained adsorbing the dye *Corresponding author.…”