Probing the Hidden Photoisomerization of a Symmetric Phosphaalkene Switch

Year: 2024

Authors: Deka R., Steen J.D., Hilbers M.F., Roeterdink W.G., Iagatti A., Xiong R.S., Buma W.J., Di Donato M., Orthaber A., Crespi S.

Autors Affiliation: Uppsala Univ, Dept Chem, Angstrom LAb, Box 523, S-75120 Uppsala, Sweden; Univ Amsterdam, Vant Hoff Inst Mol Sci, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands; Uppsala Univ, Dept Chem BMC, Box 576, S-75123 Uppsala, Sweden; Radboud Univ Nijmegen, Inst Mol & Mat, FELIX Lab, Toernooiveld 7c, NL-6525 ED Nijmegen, Netherlands; ICCOM CNR, Via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy; Lab Europeo Spettroscopia Non Lineare LENS, Via N Carrara 1, I-50019 Sesto Fiorentino, Italy; INO CNR, Largo Enrico Fermi 6, I-50125 Florence, Italy.

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.

Journal/Review: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

More Information: A.O. thanks Prof. Dr. Klaus Zangger for fruitful discussions on the PC-EXSY technique. We thank the Swedish Vetenskapsradet for a Starting Grant (2021-05414 to S.C.) and Project Grants (2017-03727 and 2021-03658 to A.O.). S.C. thanks the Stiftelsen Lars Hiertas Minne (FO2022-0139), and the Goran Gustafsson Foundation. We thank the Wenner-Gren Stiftelserna for postdoctoral stipends (UPD2022-0079 to J.D.S. and UPD2021-0023 to R.D.). The c omputations were enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS) at the Tetralith cluster (NSC in Linkoeping, thanks to the NAISS 2023/5-413 medium and 2023/22-567 small compute projects) partially funded by the Swedish Research Council through grant agreement no. 2022-06725. This project made use of the NMR Uppsala infrastructure, which is funded by the Department of Chemistry-BMC and the Disciplinary Domain of Medicine and Pharmacy, Uppsala University. The research leading to these results has received funding from LASERLAB-EUROPE (grant agreement no. 871124, European Union’s Horizon 2020 research and innovation programme, project 26745). M.D.D. and A.I. acknowledge support from the European Union’s Next Generation EU Program with the I-PHOQS Infrastructure [Nos. IR0000016, ID D2B8D520, and CUP B53C22001750006] Integrated infrastructure initiative in Photonic and Quantum Sciences.
KeyWords: Phosphaalkene; Excited state dynamics; NMR spectroscopy; Photoisomerization; Laser spectroscopy
DOI: 10.1002/anie.202419943