Toward Fractioning of Isomers through Binding-Induced Acceleration of Azobenzene Switching

Rosaria Vulcano, Paolo Pengo, Simone Velari, Johan Wouters, Alessandro De Vita, Paolo Tecilla, Davide Bonifazi

Research output: Contribution to journalArticlepeer-review

Abstract

The E/Z isomerization process of a uracil-azobenzene derivative in which the nucleobase is conjugated to a phenyldiazene tail is studied in view of its ability to form triply H-bonded complexes with a suitably complementary 2,6-diacetylamino-4-pyridine ligand. UV-vis and 1H NMR investigations of the photochemical and thermal isomerization kinetics show that the thermal Z E interconversion is 4-fold accelerated upon formation of the H-bonded complex. DFT calculations show that the formation of triple H-bonds triggers a significant elongation of the NN double bond, caused by an increase of its g∗ antibonding character. This results in a reduction of the NN torsional barrier and thus in accelerated thermal Z E isomerization. Combined with light-controlled E Z isomerization, this enables controllable fractional tuning of the two configurational isomers.

Original languageEnglish
Pages (from-to)18271-18280
Number of pages10
JournalJournal of the American Chemical Society
Volume139
Issue number50
DOIs
Publication statusPublished - 20 Dec 2017

Funding

D.B. gratefully acknowledges the Science Policy Office of the Belgian Federal Government (BELSPO-IAP 7/05 project) and the EU through the ERC COLORLAND project. P.T. and D.B. thank the HORIZON2020 Marie Sklodowska Curie Actions through the INFUSION project. R.V. thanks UNamur for her doctoral and teaching assistant position. We thank UNamur for the physical chemistry and characterization (PC2) and Bernadette Norberg for the X-ray measurements and data interpretation. We are grateful to the UK Materials and Molecular Modelling Hub for computational resources, which is partially funded by EPSRC (EP/P020194//1). A.D.V. acknowledges funding from the European Union's Horizon 2020 research and innovation program (Grant No. 676580, The NOMAD Laboratory, a European Centre of Excellence).

FundersFunder number
Horizon 2020 Framework Programme734834
European Resuscitation Council
Engineering and Physical Sciences Research CouncilEP/P020194//1
European External Action Service
Horizon 2020676580

    Fingerprint

    Dive into the research topics of 'Toward Fractioning of Isomers through Binding-Induced Acceleration of Azobenzene Switching'. Together they form a unique fingerprint.

    Cite this