November 2, 2024

Chemistry Breakthrough: Scientists Take Photoclick Chemistry to the Next Level

Graphical abstract of the research. Credit: UvA HIMS/ ChemSci
Photoclick chemistry is a light-activated range of click chemistry (Nobel Prize in Chemistry 2022), a set of classy and efficient chemical reaction approaches that couple devoted molecular units to yield wanted items. Photoclick chemistry has special benefits over standard click chemistry as it enables a high degree of both spatial and temporal control over the reaction It has a broad series of applications, consisting of 3D printing, protein labeling, and bioimaging.
An increase for the PQ-ERA photoclick response.
A specific photoclick reaction is the so-called PQ-ERA reaction– the light-induced photocycloaddition of 9,10-phenanthrenequinone (PQ) with electron-rich alkenes (ERA). Due to the fact that of its excellent kinetics and biocompatibility, it has drawn much attention. However, the traditionally used PQ compounds show restricted reactivity, which prevents its total performance.
In the study now presented in Chemical Science, the international research study team provides an easy method to alter that. They describe how a thiophene alternative at the 3-position of the PQ scaffold considerably improves the reactivity of the PQ triplet state to enhance the effectiveness of the PQ-ERA response.
Nanosecond time-resolved spectroscopic research studies and quantum chemical studies in the Amsterdam Molecular Photonics group combined with femtosecond time-resolved spectroscopic research studies carried out in Florence provided a fundamental understanding of this particular photoclick chemistry. The examinations show that the alternative substantially increases the population of the reactive triplet state (3ππ *) throughout excitation of 3-thiophene PQs. This results in an exceptional photoreaction quantum yield (FP, up to 98%), high second-order rate constants (k2, approximately 1974 M − 1 s − 1), and noteworthy oxygen tolerance for the PQ-ERA reaction system.
These outcomes now pave the way for an additional improvement of the response, providing outstanding prospects for fast and efficient photoclick transformations.
Reference: “Establishing PQ-ERA photoclick reactions with unprecedented effectiveness by engineering of the nature of the phenanthraquinone triplet state” by Youxin Fu, Georgios Alachouzos, Nadja A. Simeth, Mariangela Di Donato, Michiel F. Hilbers, Wybren Jan Buma, Wiktor Szymanski and Ben L. Feringa, 21 June 2023, Chemical Science.DOI: 10.1039/ D3SC01760E.

Photoclick chemistry is a light-activated range of click chemistry (Nobel Prize in Chemistry 2022), a set of elegant and effective chemical response techniques that pair dedicated molecular units to yield wanted products. A specific photoclick response is the so-called PQ-ERA reaction– the light-induced photocycloaddition of 9,10-phenanthrenequinone (PQ) with electron-rich alkenes (ERA). The conventionally used PQ substances reveal limited reactivity, which hinders its overall performance.
Nanosecond time-resolved spectroscopic studies and quantum chemical research studies in the Amsterdam Molecular Photonics group integrated with femtosecond time-resolved spectroscopic studies performed in Florence provided a basic understanding of this particular photoclick chemistry.

Scientists have substantially enhanced the effectiveness of photoclick chemistry. Utilizing molecular alternatives, they boosted the reactivity of the PQ-ERA response, causing greater quantum yields and reaction rates.
Through a collective effort including the Universities of Groningen and Amsterdam in the Netherlands, in addition to Italys European Laboratory for Non-Linear Spectroscopy, researchers have substantially sophisticated photoclick chemistry. They improved the reactivity of the photoclick compound used in the widely-utilized PQ-ERA reaction through tactical molecular alternative.
In Chemical Science, the flagship journal of the Royal Society of Chemistry, they report a superb photoreaction quantum yield, high reaction rates, and notable oxygen tolerance. The paper was designated a HOT Article along with Pick of the Week.
At the University of Amsterdam, Michiel Hilbers and Wybren Jan Buma of the Molecular Photonics group (Vant Hoff Institute for Molecular Sciences) added to the research study of which the artificial and response characterization part was conducted in the labs of Wiktor Szymanski and Nobel laureate Ben Feringa at the University of Groningen.