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. 2025 Jan 27;64(5):e202419943.
doi: 10.1002/anie.202419943. Epub 2024 Dec 13.

Probing the Hidden Photoisomerization of a Symmetric Phosphaalkene Switch

Rajesh Deka  1 , Jorn D Steen  1 , Michiel F Hilbers  2 , Wim G Roeterdink  2 , Alessandro Iagatti  3   4 , Ruisheng Xiong  5 , Wybren Jan Buma  2   6 , Mariangela Di Donato  7   3 , Andreas Orthaber  1 , Stefano Crespi  1
Affiliations

Probing the Hidden Photoisomerization of a Symmetric Phosphaalkene Switch

Rajesh Deka et al. Angew Chem Int Ed Engl. .

Abstract

In this study, we present the synthesis and analysis of a novel, air-stable, and solvent-resistant phosphaalkene switch. Using this symmetric switch, we have demonstrated degenerate photoisomerization experimentally for the first time. With a combination of photochemical-exchange NMR spectroscopy, ultrafast transient absorption spectroscopy, and quantum chemical calculations, we elucidate the isomerization mechanism of this symmetric phosphaalkene, comparing it to two other known molecules belonging to this class. Our findings highlight the critical role of the isolobal analogy between C=P and C=C bonds in governing nanoscale molecular motion and break new ground for our understanding of light-induced molecular processes in symmetric heteroalkene systems.

Keywords: Excited state dynamics; Laser spectroscopy; NMR spectroscopy; Phosphaalkene; Photoisomerization.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
a. Ground and excited state isomerization modes of C=N and C=C double bonds. b. Examples of imine and alkene photoswitches. c. An example of a phosphalkene photoswitch. d. Present work.
Figure 2
Figure 2
a. Synthesis of phosphaalkene 1. Inset: X‐ray structure of 1. Thermal displacement ellipsoids are set at 50 % probability levels, hydrogen atoms are omitted, and the Mes* group is shown as a wireframe for clarity. b. Molar absorptivity of 1 in different solvents.
Figure 3
Figure 3
a. PC‐EXSY experiment. b. Evolution Associated Difference Spectra (EADS) obtained from a global fit of the femtosecond transient absorption spectral data recorded of 1 in toluene. c. Potential energy surfaces of the S0 and S1 states of 1 obtained by geometry optimization using CREST3 followed by single‐point calculation using MRSF‐TDDFT. d. Energy diagram of the different transition states (TS and TS′) found for the thermal double‐bond isomerization of 1 at the MRSF‐TDDFT/6‐31G*/6‐311G* level.
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References

    1. Pianowski Z. L., Ed., Molecular Photoswitches: Chemistry, Properties, and Applications, 2 Volume Set, Wiley; 2022.
    1. Wang H., Bisoyi H. K., Zhang X., Hassan F., Li Q., Chem. Eur. J. 2022, 28, e202103906. - PubMed
    1. Kathan M., Crespi S., Thiel N. O., Stares D. L., Morsa D., de Boer J., Pacella G., van den Enk T., Kobauri P., Portale G., Schalley C. A., Feringa B. L., Nat. Nanotechnol. 2022, 17, 159–165. - PMC - PubMed
    1. Corra S., Curcio M., Credi A., JACS Au 2023, 3, 1301–1313. - PMC - PubMed
    1. Čechová L., Filo J., Dračínský M., Slavov C., Sun D., Janeba Z., Slanina T., Wachtveitl J., Procházková E., Cigáň M., Angew. Chem. Int. Ed. 2020, 59, 15590–15594. - PubMed

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