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Updated: Mar 19, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Extended Aromatic and Heteroaromatic Ring Systems in the Chalcone-Flavanone Molecular Switch Scaffold
Brian M Muller1, Theodore J Litberg1, Reid A Yocum1
1Department of Chemistry and Biochemistry, Northern Illinois University , 1425 W. Lincoln Hwy, DeKalb, Illinois 60115, United States.
Abstract:
Previous work on the o-hydroxychalcone/flavanone molecular switching scaffold showed that simple substitutions alter the pH range in which rapid interconversion occurs. Herein, more impactful structural modifications were performed via alteration of the characteristic phenyl rings to alternative aromatic systems. It was determined that the scaffold was still viable after these changes and that the range of accessible midpoint pH values was markedly increased. To further explore the switch's scope, scaffolds able to have multiple switching events were also investigated.
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