Laser-induced temperature dependent triplet state lifetime of rubreneperoxide

A number of photophysical properties of three different types of rubreneperoxides have been measured experimentally by flash spectroscopy technique, including the two-photon absorption, fluorescence, delayed fluorescence and temperature dependent triplet-triplet absorption spectra. Excited singlet and triplet state lifetimes are temperature dependent. Lowest triplet state lifetimes were measured from 77 K to 50 °C. Experimental observations showed that as we decreased the temperature of rubreneperoxides, most of the molecules migrate to the lowest vibrational and rotational energy levels of the ground electronic state. Similar migration is also observed for the lowest triplet state. Therefore at 77 K, we can get the clean absorption an emission spectra and decay curves for the lowest triplet state. At 50 °C, due to the P- and/or E-type of delayed fluorescences, decay of T1 state, in other words disappearance of the T1 state is becoming faster than at low temperature (below room temperature).