Pathways to fluorescence via restriction of intramolecular motion in substituted tetraphenylethylenes

0552058 - ÚOCHB 2023 RIV GB eng J - Journal Article
Li, Y. - Aquino, A. J. A. - Siddique, F. - Niehaus, T. A. - Lischka, H. - Nachtigallová, Dana
Pathways to fluorescence via restriction of intramolecular motion in substituted tetraphenylethylenes.
Physical Chemistry Chemical Physics. Roč. 24, č. 3 (2022), s. 1722-1735. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR(CZ) GX19-27454X
Institutional support: RVO:61388963
Keywords : aggregation-induced emission * gaussian-basis sets * molecular dynamics
OECD category: Physical chemistry
Impact factor: 3.3, year: 2022
Method of publishing: Limited access
https://doi.org/10.1039/D1CP04848A

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.
Permanent Link: http://hdl.handle.net/11104/0327220