Time resolved hole burning

We have done a study by time-resolved hole-burning spectroscopy for dye molecules in polar solvents and found that the time correlation function of the hole width decays much slower than that of the peak shift of the hole, which occurs very rapidly, as you observed in the case of the fluorescence Stokes shift [K. Nishiyama, Y. Asano, N. Hashimoto, and T. Okada, J. Mol. Liquids 65/66, 41 (1995)]. 

Solvation Dynamics of Dye Molecules in Polar Solvents Studied by Time Resolved Hole Burning Spectroscopy... 

Time resolved hole burning spectra were measured by means of a femtosecond transient absorption spectrometer system. A second harmonics of a mode locked cw Nd + YAG laser (Quantronix, 82MHz) was used for a pumping source. A synchronously pumped rhodamine 6G dye laser with a saturable absorber dye jet (DODCl/DQOCI) and dispersion compensating prisms in the cavity was used. The output of the dye laser (lOOfs fwhm, 600pJ/pulse) was... 

A treatment for analysing the excitation and fluorescence multiwavelength polarized decay surfaces has been given for the case of a mixture of noninteracting species. An improved model for analysis of fluorescence anisotropy measurements has been presented. Limitations to the use of intense excitation pulses in fluorescence and thermal lens spectrophotometers are discussed in terms of optical saturation. Such artefacts can be eliminated by reference to the fluorescence quantum yield of Rhodamine 6G. A model has been given to describe spectral diffusion in time-resolved hole-burning spectroscopy. ... 

Loring R F, Van Y J and Mukamel S 1987 Time-resolved fluorescence and hole-burning line shapes of solvated molecules longitudinal dielectric relaxation and vibrational dynamics J. Chem. Phys. 87 5840-57... 

Vogel W, Welsch D-G and Wilhelm B 1988 Time-resolved spectral hole burning Chem. Phys. Lett. 153 376-8... 

Murakami H, Kinoshita S, Hirata Y, Okada T and Mataga N 1992 Transient hole-burning and time-resolved fluorescence spectra of dye molecules in solution evidence for ground-state relaxation and hole-filling effect J. Chem. Phys. 97 7881-8... 

Pairwise EET rates cannot be directly measured in antenna systems. The closest approach to direct determination is offered on the one hand by time resolved picosecond and sub-picosecond absorption and fluorescence measurements and on the other hand by hole burning spectroscopies. Time resolved techniques do not detect transfer between isoenergetic sites. A somewhat more indirect approach to determining pairwise rates is that of analysing excited state lifetime data in terms of a particular antenna and an EET model. 

The time-resolved solvation of s-tetrazine in propylene carbonate is studied by ultrafast transient hole burning. In agreement with mode-coupling theory, the temperature dependence of the average relaxation dme follows a power law in which the critical temperature and exponent are the same as in other relaxation experiments. Our recent theory for solvation by mechanical relaxation provides a unified and quantitative explanation of both the subpicosecond phonon-induced relaxation and the slower structural relaxation. 

In the extended CM, the JG relaxation is just part of the continuous evolution of the dynamics. The JG relaxation should not be represented by a Cole-Cole or Havriliak-Negami distribution, as customarily assumed in the literature, and considered as an additive contribution to the distribution obtained from the Kohlrausch a-relaxation. Nevertheless, the JG relaxation may be broadly defined to include all the relaxation processes that have transpired with time up until the onset of the Kohlrausch a-relaxation. Within this definition of the JG relaxation, experiments performed to probe it will find that essentially all molecules contribute to the JG relaxation and the motions are dynamically and spatially heterogeneous as found by dielectric hole burning [180,283] and deuteron NMR [284] experiments. This coupling model description of the JG relaxation may help to resolve the different points of view of its nature between Johari [285] and others [180,226,227,280,281,283,284],... 

It is not surprising that the triplet states of porphyrins attract interest. A comprehensive study of some purpurins with Sn(lV) substitution involving observations of absorption, fluorescence and triplet spectra and 2 formation and the triplet state of sapphyrin dication (a large porphyrin like system) shows an unusual spin alignment in the monomer and spin delocalization in dimers " are systems of photophysical interest. The influence of external parameters on time resolved transient hole burning in porphyrins shows the effects of a triplet state bottleneck in the rate of state build up". ... 

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