<br>磷光的第一原理检验,RSC Advances

当前位置： X-MOL 学术 › RSC Adv. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

磷光的第一原理检验
RSC Advances ( IF 3.9 ) Pub Date : 2022-09-07 , DOI: 10.1039/d2ra03447f
Anjay Manian ₁ , Igor Lyskov ₁ , Robert A Shaw ₂ , Salvy P Russo ₁

Affiliation

本文从第一原理的角度探讨了磷光，并研究了计算自旋禁阻T ₁ → S ₀跃迁偶极矩所涉及的复杂性，以强调该机制的计算并不像看起来那么复杂。使用气相吖啶作为案例研究，我们通过将第一个三重激发态耦合到S ₄和T ₄态，打破了计算 Franck-Condon 和 Herzberg-Teller 体系中磷光光谱所需的形式。尽管第一单重激发态表现为L _b态而不是nπ*特征，但发现二阶校正速率常数为0.402 s ^-1 ，与吖啶衍生物的实验磷光寿命相比较。在显示仅需要某些状态来准确描述矩阵元素以及如何找到这些状态时，我们的计算表明 nπ* 状态仅与T ₁状态弱耦合。这表明它的重要性取决于其猝灭荧光和增强非辐射机制的能力，而不是其对跃迁偶极矩的贡献。对T ₁ → S ₀跃迁偶极矩的增长作为其与其他电子态耦合函数的后续研究强调，主导矩阵元素的项完全来自包含具有强自旋轨道耦合项的状态。这意味着虽然跃迁偶极矩的扩展可以扩展到包括无限数量的电子态，但只需要包括某些状态。

"点击查看英文标题和摘要"

A first principles examination of phosphorescence

This paper explores phosphorescence from a first principles standpoint, and examines the intricacies involved in calculating the spin-forbidden T₁ → S₀ transition dipole moment, to highlight that the mechanism is not as complicated to compute as it seems. Using gas phase acridine as a case study, we break down the formalism required to compute the phosphorescent spectra within both the Franck–Condon and Herzberg–Teller regimes by coupling the first triplet excited state up to the S₄ and T₄ states. Despite the first singlet excited state appearing as an L_b state and not of nπ* character, the second order corrected rate constant was found to be 0.402 s⁻¹, comparing well with experimental phosphorescent lifetimes of acridine derivatives. In showing only certain states are required to accurately describe the matrix elements as well as how to find these states, our calculations suggest that the nπ* state only weakly couples to the T₁ state. This suggest its importance hinges on its ability to quench fluorescence and exalt non-radiative mechanisms rather than its contribution to the transition dipole moment. A followup investigation into the T₁ → S₀ transition dipole moment's growth as a function of its coupling to other electronic states highlights that terms dominating the matrix element arise entirely from the inclusion of states with strong spin–orbit coupling terms. This means that while the expansion of the transition dipole moment can extend to include an infinite number of electronic states, only certain states need to be included.

更新日期：2022-09-07

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南