Volume 89, Issue 2 e202300504
Research Article

A Synthetic Approach for Oxadiazole-Decorated Azobenzene Photoswitches

Adela F. Dobre

Adela F. Dobre

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

These authors contributed equally.

Contribution: Formal analysis (lead), ​Investigation (lead), Methodology (supporting), Visualization (lead), Writing - original draft (equal), Writing - review & editing (supporting)

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Dr. Anamaria Hanganu

Dr. Anamaria Hanganu

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

“C. D. Nenitzescu“ Institute of Organic and Supramolecular Chemistry of the Romanian Academy, 202B Spl. Independenţei, 060023 Bucharest, Romania

These authors contributed equally.

Contribution: Data curation (equal), Formal analysis (equal), ​Investigation (equal), Validation (equal), Visualization (equal), Writing - original draft (equal)

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Dr. Ioana Nicolau

Dr. Ioana Nicolau

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

These authors contributed equally.

Contribution: Data curation (equal), Formal analysis (equal), ​Investigation (equal), Methodology (equal), Visualization (equal)

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Dr. Codruta C. Popescu

Dr. Codruta C. Popescu

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Contribution: Formal analysis (supporting), ​Investigation (supporting), Methodology (supporting), Project administration (supporting), Resources (supporting), Validation (supporting), Visualization (supporting), Writing - review & editing (supporting)

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Dr. Anca Paun

Dr. Anca Paun

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Contribution: Data curation (supporting), Formal analysis (supporting), ​Investigation (supporting), Validation (supporting)

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Dr. Augustin M. Mădălan

Dr. Augustin M. Mădălan

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Contribution: Data curation (lead), Formal analysis (lead), ​Investigation (lead), Methodology (lead), Software (lead), Writing - original draft (equal), Writing - review & editing (equal)

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Dr. Cristina Tablet

Dr. Cristina Tablet

Faculty of Pharmacy, Titu Maiorescu University, Gh. Sincai Bd. 16, 040317 Bucharest, Romania

Contribution: Data curation (lead), Formal analysis (lead), ​Investigation (lead), Methodology (lead), Software (lead), Validation (lead), Writing - original draft (lead)

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Dr. Anca G. Mirea

Dr. Anca G. Mirea

National Institute of Material Physics, 405 A Atomistilor Street, 077125 Magurele, Romania

Contribution: ​Investigation (supporting), Validation (supporting), Writing - review & editing (supporting)

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Dr. Mihaela Matache

Corresponding Author

Dr. Mihaela Matache

Faculty of Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Research Centre of Applied Organic Chemistry, University of Bucharest, 90 Panduri Street, 050663 Bucharest, Romania

Contribution: Conceptualization (lead), Data curation (lead), Funding acquisition (lead), ​Investigation (lead), Methodology (lead), Project administration (lead), Resources (lead), Supervision (lead), Validation (lead), Writing - original draft (lead), Writing - review & editing (lead)

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First published: 26 October 2023

Graphical Abstract

The synthesis of novel oxadiazole-decorated azobenzenes using amino functionalised heterocyclic intermediates used either to provide electrophilic diazonium salts able to react with phenols or as nucleophilic partners in Bayer-Mills reaction is reported in this work. The oxadiazole-decorated azobenzenes were used in irradiation experiments to determine the parameters that characterize a photoswitch, yielding appealing results. The experimental results were very well correlated with DFT calculations.

Abstract

This work reports the design and synthesis of novel oxadiazole-decorated azobenzenes, structural analysis of the resulting compounds and behavior under light irradiation. The synthetic strategy involved constructing amino functionalized heterocyclic key intermediates which were used either to yield electrophilic diazonium salts able to react with phenol moieties or as nucleophilic partners in Bayer-Mills reaction with nitroso-substituted derivatives. The amino-derived oxadiazole intermediates were investigated by absorption and emission spectroscopy providing blue and green emitted light. The target oxadiazole-decorated azobenzenes were structurally characterized, including solid-state structures, and subsequently used in irradiation experiments in order to take advantage of the azo group known to provide photoswitching abilities. We noticed quenching of the emissive properties in presence of the azo group; however, all compounds were very stable to repeated cycles of light irradiation. In addition, according to structural diversification we could obtain half-lives of the meta stable isomers within hours to hundreds of hours range. The experimental results were very well correlated with DFT calculations.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.