Novel fluorescence probe based on pyrene and piperazine; spectral properties in solution and in polymer matrices

New fluorescence probe, composed of pyrene and piperazine [15-(1-pyrenyl)-7,15-diazadispiro[5,1,5,3]hexadecane] was prepared, spectrally characterized and its properties compared with its precursors as pyrene and 1-bromopyrene. Spectral measurements were performed in solution (methanol, chloroform, cyclohexane) and in polymer matrices as polystyrene, polymethyl methacrylate and polyvinylchloride. Absorption spectra of the probe exhibited less resolved vibrational spectra as its constituents as pyrene or 1-bromopyrene. Absorption spectra of the probe have got similar shape in solvents as well as in all used polymer. Fluorescence spectrum of the probe represents a broad band without any vibrational structure in all solvents and polymers matrices. The vibrational structure of fluorescence of pyrene and 1-bromopyrene under the same conditions is well preserved in absorption as well as in emission spectra. Quantum yield of fluorescence of the probe is slightly higher than anthracene in methanol. The quantum yield of the probe relative to anthracene lies in the range 2–9 in solvents and polymer matrices and it is influenced by oxygen. The lifetime of fluorescence of novel probe is around 5 ns. The position of the maximum of fluorescence spectra is shifted bathochromically with the concentration of the probe in polymer film, which is not observed for pyrene and 1-bromopyrene under the same conditions. The character of the excited state of the probe is discussed.