Exploration of aminomethylene linkage in carbazole based donor-pi-acceptor molecules for AIE properties and hydrazine sensing

Abstract

Carbazole based donor-pi-acceptor molecules with various active methylene compounds attached via aminomethylene and azo linkages are designed. All the compounds are synthesized, characterized and studied for their photophysical properties. Newly introduced aminomethylene linkage in carbazole based donor-pi-acceptor molecules is showing significant effect on absorbance and emission band of all the studied compounds attached to various acceptor moieties. All the compounds with aminomethylene linkages are showing very good fluorescence in solid, aggregation and solution. While azo linked barbituric acid derivatives are showing significant red shift in emission band. Carbazole linked to barbituric acid using both aminomethylene and azo linkages are studied for hydrazine detection and showed significant difference. NLO properties for all the compounds from both the series are calculated using DFT calculation and azo linkage is found to show prominent enhancement in the first order hyperpolarizability (β) values.