Investigating structural dynamics and sensing capabilities: Spectroscopic and DFT analysis of novel AIEE active deferasirox based organic sensor

Abstract

A deferasirox based sensor DPA was rationally designed through single step amidation reaction. Sensor DPA exhibited aggregation induced emission enhancement (AIEE) property that was attributed to restriction in intramolecular rotation (RIR). Moreover, the sensor DPA displayed remarkable bathochromic shift (red-shift) of 110 nm in wavelength, ascribed to formation of J-aggregates. Furthermore, sensor DPA was employed for the selective and sensitive fluorescence based sensing of hazardous and carcinogenic nitrobenzene (NB). The sensor DPA successfully detected NB in solution through the quenching of emission intensity. The quenching of sensor fluorescence intensity was ascribed to photoinduced electron transfer (PET) mechanism. The sensing mechanism was investigated by 1H NMR titration experiment, Job's plot and density functional theory (DFT) calculations. Additionally, the existence of non-covalent interactions between sensor DPA and NB were examined by Bader's Quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analysis. Finally, sensor DPA was employed for the detection of volatile nitrobenzene in vapor phase.