Abstract

Transient absorption spectroscopy uses short laser pulses which can be up to tens of femtoseconds. These pulses can effectively “freeze” the motion of the molecules at specific times during a reaction or a dynamic process, and by modification of the time delay between the pump and probe pulses snapshots of the molecular system can be obtained at different stages of its evolution, providing insights into the underlying dynamics. For this purpose, the nanosecond or femtosecond transient absorption techniques can be utilized. In this presentation ultrafast spectroscopy (transient absorption) and emission (steady state and time-resolved fluorescence) spectroscopy were applied for to study and characterize the photophysical properties of some phthalocyanine derivatives. For this, new compounds (phthalocyanine derivatives) have been synthesized and the quantum yields and lifetimes of excited states were estimated. Also, to demonstrate excited-state processes from the transient absorption map, we obtained a ground state bleaching band (GBS), absorption in excited state (ESA) and at longer wavelength, stimulated emission (SE).