Exploring the nitro group reduction in low-solubility oligo-phenylenevinylene systems: Rapid synthesis of amino derivatives

Abstract

A small series of amino oligo-phenylenevinylenes (OPVs) were successfully synthesized from their nitro-analogs in a rapid, simple, and highly efficient fashion employing a sodium sulfide/pyridine system as a reducing agent. In this research, classic and sustainable reduction methodologies including NH₄HCO₂/Zn and a choline chloride/tin (II) chloride deep eutectic solvent (DES) were also evaluated, showing degradation products, incomplete reactivity, and product isolation difficulties in all cases. The straightforward Na₂S/pyridine synthetic protocol proved to maintain the E-E stereochemistry of the OPV backbone that has been previously assembled by the Mizoroki–Heck cross-coupling reaction. Also, the optoelectronic properties were determined and discussed, considering the amino group insertion in these conjugated systems as a contribution for future construction of novel materials with applications in supramolecular electronics, light harvesting, and photocatalysis.

Graphical Abstract

Keywords:

• Amino phenylenevinylene
• Mizoroki–Heck reaction
• nitro reduction
• optoelectronic properties

Acknowledgments

We want to thank Laboratorio de Espectrometria de Masas – PTG – Universidad Industrial de Santander for data acquisition.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by Colciencias [project N° FP44842-025-2017], DIB-UNAL [project with code HERMES 36990] and the Teaching Assistant Scholarship Program of Universidad Nacional de Colombia.