Pathways to fluorescence via restriction of intramolecular motion in substituted tetraphenylethylenes
Pathways to fluorescence via restriction of intramolecular motion in substituted tetraphenylethylenes
复制标题
通过限制取代四苯乙烯的分子内运动产生荧光的途径
DOI：
10.1039/d1cp04848a
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发表时间：
2022
影响因子：
3.3
通讯作者：
Nachtigallová, Dana
中科院分区：
文献类型：
--
作者：
Li, Yingchao;Aquino, Adélia J.;Siddique, Farhan;Niehaus, Thomas A.;Lischka, Hans;Nachtigallová, Dana
具有增强的发光性能的材料的设计是一个快速发展的领域，由于这些材料作为发光二极管或用于生物成像的潜在适用性。增强感兴趣的候选分子的发射性质的一个透明的方法是通过限制分子内运动来阻断竞争和非生产性的非辐射弛豫途径。非物质化功能化是实现这种限制的重要可能性。采用基于ω B 97 XD泛函的含时密度泛函理论（TD-DFT）和包含长程修正的半经验紧束缚方法（TD-LC-DFTB），研究了四苯乙烯（TPE）的功能化对实现锥形交叉受限通道（RACI）的影响.光动力学表面跳跃模拟已经进行了一个更大的一组化合物，包括TPE和10个官能化的TPE化合物。通过吸电子基团、通过空间位阻阻断弛豫通道的大体积基团和能够形成强氢键的基团实现了官能化，所述基团通过形成氢键通道限制运动。大多数研究的官能化TPE候选物由于其仍然存在的结构灵活性而显示出超快失活至基态，但是两个实例，一个含有-CN和-CF 3基团，第二个以氢键网络为特征，已被确定为用于在溶液中产生有效发光性质的感兴趣的候选物。
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.