Frequency shift and dephasing of the S₁ ← S₀ transition of free-base porphin in an n-octane crystal as a function of temperature

We report a study of the temperature dependence of the homogeneous width and frequency of the S1 ← S0 0-0 transition of free-base porphin as a guest in an n-octane matrix. In the liquid helium temperature region, the measurements have been made by means of photochemical hole-burning, at higher temperatures up to 90 K via an analysis of the fluorescence spectrum. The results are interpreted in terms of the "exchange model" for optical dephasing. © 1978.