Synthesis, physicochemical, optical, thermal and TD-DFT of (E)-N′-((9-ethyl-9H-carbazol-3-yl)-methylene)-4-methyl-benzene-sulfonohydrazide (ECMMBSH): Naked eye and colorimetric Cu2+ ion chemosensor

Benzene-sulfonohydrazide (ECMMBSH) Schiff base has been made available in an excellent yield via reflux dehydrate of 4-methylbenzene-sulfonohydrazide with 9-ethyl-9H-carbazole-3-carbaldehyde in EtOH. The synthesis of the ECMMBSH was monitored via two main spectroscopic techniques FT-IR and UV–vis tools; ECMMBSH was characterized via MS, 1H NMR, FT-IR, CHN-EA, TG/DTG, EDX, and UV–vis., analysis. Moreover, DFT-optimized, Molecular Electrostatic Potential (MEP) and MAC/NPA-charge models were performed for ECMMBSH. The HOMO/LUMO and Density of State (DOS) calculated energy levels were compared to Tuac experimental optical energy gap values in methanol. Additionally, the TD-DFT and UV–vis. experimental absorption behavior was matched under the same condition. Moreover, the chemo-sensation effect of the ECMMBSH towered Cu2+ ions via complexation was evaluated by naked eye in addition to the UV–vis spectrophotometric measurements.