Synthesis, characterization and investigation of photophysical properties of 1,3,4-thiadiazole compounds containing phenanthroimidazole structure

Fluorescence properties of organic compounds are one of the most remarkable disciplines or organic materials. Fluorescent organic compounds, especially nitrogen-containing heterocyclic compounds, attract the attention of researchers due to their efficiency. Within the scope of te thesis, phenanthroimidazole-tiadiazole hybrid compounds, which are new heterocyclic molecules with fluorescent properties, were designed with a two-stage reaction mechanism, synthesized and their photophysical properties were investigated. The synthesized compounds were purified and characterized by ATR-IR, 1H-NMR, mass and elemental analysis. In the next part of the study, the absorption and emission spectra of the new compounds were measured by UV-Vis and fluorescence spectroscopy. Stokes' shifts, singlet energy levels (Es), molar extinction coefficients (ε), lifetimes (τ), quantum yield (ϕf), the radiative (kr) and the nonradiative (knr) constant for new hybrid derivatives were determined fort he compounds. The changes in the absorption and fluorescence emission peaks in solvents of different polarities were investigated by the bonding of electron withdrawing and electron donating groups to the ortho-, meta- and para- positions of the molecule. In addition, aggregation measurement, which is an important parameter that changes the photophysical properties, were carried and the molecular structure: photophysical properties were investigated. It is thought that the synthesized compounds may find applications in different technologies such as fluorescent laser dyes, solar cells, OLED technology and sensors thanks to their high π conjugation system and their advanced photophysical properties.