Synthesis, characterization, band gap and optical properties of new pyromellittic diimide core dervatives

This study is an overview of recent advances in development of high performance diimide derivatives and their optical properties. It covered pyromellitic diimide that conjugated a 1,2,3-triazole heterocyclic molecules containing π-conjugated molecules, which gave the molecule optoelectronic properties. The new N-amino diimide compound [1] was prepared from hydrazine and pyromellitic dianhydride which could react with chloroacetyl chloride controlled by heat to give N,N - bis (2-amino acetyl chloride) pyromellitic diimide [2] then react with sodium azide to give N,N - bis (2-amino acetyl azide) pyromellitic diimide [3] that could conjugate with α-β unsaturated aldehyde derivatives when heated at 110°C for 24 hrs to give 1,2,3-triazole heterocyclic. The prepared compounds were characterized by FT-IR spectrum and 1H-NMR and physical properties. The UV-vis spectrum showed the maximum wavelength for the prepared compounds ˃200 nm where the calculated direct band gap energy from tauc model for expected transition state was about ≥ 4.7 ev. The studied energy gap for prepared compounds approved the energy gap that decreased by about 0.1 ev when their molecule had π-electron, which conjugated with π eletrons in 1,2,3-triazole heterocyclic ring.