Imidazo[1,2-c]pyrimidine Azo-Dyes: Synthesis, Characterization, DFT, and Fluorescence Properties

An efficient synthetic approach for a new class of imidazopyrimidine-azo dyes as good fluorophores is proposed. The approach comprises of synthesis of 2-thioxocytosine, then cyclization to imidazo[1,2-c]pyrimidine by treating with chloroacetyl chloride. Finally, azo dyes were accomplished by functionalization at α-CH site. The chemical modification of the chromophores was achieved by introducing electron withdrawing and donating groups for studying the effect of electronic capacity on the photophysical characteristics of the fluorophores. Spectral investigations for a group of the synthesized imidazopyrimidine-azo dyes demonstrated good fluorescent properties, with maxima absorptions at 335–355 nm and emissions at 430.6–459.8 nm. Following optimization in their fundamental states, the geometric and electrical properties of these investigated compounds are computed using DFT/B3LYP/6-311G(d,p). Many metrics have been explored using this method, including the molecular electrostatic potential (MEP), the band gap, chemical reactivity indices, border molecular orbital, and the HOMO and LUMO energy levels.