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Li Y, Aquino AJA, Siddique F, Niehaus TA, Lischka H, Nachtigallová D. Pathways to fluorescence via restriction of intramolecular motion in substituted tetraphenylethylenes. Phys Chem Chem Phys 2022; 24:1722-1735. [PMID: 34984424 DOI: 10.1039/d1cp04848a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The design of materials with enhanced luminescence properties is a fast-developing field due to the potential applicability of these materials as light-emitting diodes or for bioimaging. A transparent way to enhance the emission properties of interesting molecular candidates is blocking competing and unproductive non-radiative relaxation pathways by the restriction of intramolecular motions. Rationalized functionalization is an important possibility to achieve such restrictions. Using time-dependent density functional theory (TD-DFT) based on the ωB97XD functional and the semiempirical tight-binding method including long-range corrections (TD-LC-DFTB), this work investigates the effect of functionalization of the paradigmatic tetraphenylethylene (TPE) on achieving restricted access to conical intersections (RACI). Photodynamical surface hopping simulations have been performed on a larger set of compounds including TPE and ten functionalized TPE compounds. Functionalization has been achieved by means of electron-withdrawing groups, bulky groups which block the relaxation channels via steric hindrance and groups capable of forming strong hydrogen bonds, which restrict the motion via the formation of hydrogen bond channels. Most of the investigated functionalized TPE candidates show ultrafast deactivation to the ground state due to their still existing structural flexibility, but two examples, one containing -CN and -CF3 groups and a second characterized by a network of hydrogen bonds, have been identified as interesting candidates for creating efficient luminescence properties in solution.
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Affiliation(s)
- Yingchao Li
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, P. R. China.
| | - Adélia J A Aquino
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, P. R. China. .,Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, 79409, USA
| | - Farhan Siddique
- Department of Pharmaceutical Chemistry, Bahauddin Zakariya University, 60800 Multan, Pakistan.,Royal Institute of Medical Sciences, Multan, Pakistan
| | - Thomas A Niehaus
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622, Villeurbanne, France
| | - Hans Lischka
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, P. R. China. .,Department of Chemistry and Biochemistry, Texas Tech University Lubbock, TX 79409-1061, USA
| | - Dana Nachtigallová
- Institute of Organic Chemistry and Biochemistry v.v.i., The Czech Academy of Sciences, 16610 Prague 6, Czech Republic. .,IT4Innovations, VŠB-Technical University of Ostrava, 70800 Ostrava-Poruba, Czech Republic
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