| Abstract [eng] |
Karolis Gineitis. Ultrafast proton transfer dynamics in pyrano[2,3-c]pyrazol derivatives. Fused pyrazole derivatives represent an important class of organic compounds and find different applications as functional materials. A new sub-class of these compounds was recently synthesyzed by A. Urbonavičius et al. [1], proposing them as analogues to the already popular 3-HF class of molecules. The main feature of these molecules is a pronounced double wavelength fluorescence, which is attributed to excited state proton transfer. The purpose of this work is to gather never seen before kinetic data of the new pyrano[2,3-c] pyrazol derivatives and provide an initial interpretation of the underlying photophysical processes. We present transient absorption and time-resolved fluorescence data alongside a proposed kinetic model for one of the derivatives dissolved in methanol. Complementary measurements in chloroform are also presented, however no distinct model is discussed, since the dynamics appear to be complicated. Finally, „dark“ states of the ground electronic state are probed by pump-dump- probe spectroscopy, again, showing convoluted underlying processes. Overall, the new class of pyrano[2,3-c]pyrazol compounds appears to be rich in interesting photodynamics and could potentially become a model system for proton transfer related photophysics, much like the popular 3-hydroxyflavones. |
