Elucidating the mechanism for light emission in donor-acceptor functionalized, symmetry-broken triaryl methyl radicals and polyradicals

在这个项目中，我们将调查和解开卤代三苯甲基自由基的过渡，导致他们的光致发光。理论计算将伴随着实验并得到验证。我们将合成新的供体官能化的和不对称的三苯甲基自由基和多自由基，以开辟否则禁止弛豫途径。这将有助于我们理解导致光发射的过程，并开发具有前所未有的短弛豫时间和高光致发光量子产率的高性能自由基发射体。为了找到具有最大性能的系统，将使用量子化学计算进行不同取代的三苯甲基自由基的筛选。取代的自由基将被筛选的快速衰变率使用无限制的简化TD-DFT识别系统与大振子强度。此外，我们将确定D 0和D1-状态之间的圆锥交叉点的最小能量，以获得有关非辐射衰变和转移率的信息。为此，我们将开发一个无限制版本的孔-孔-Tamm-Dancoff近似密度泛函理论方法（hh-TDA）。

In this project, we will investigate and unravel the transitions in halogenated trityl radicals that lead to their photoluminescence. Theoretical calculations will be accompanied and validated by experiments. We will synthesize new donor-functionalized and asymmetric trityl radicals and polyradicals to open up otherwise symmetry-forbidden relaxation pathways. This will help us to understand the processes that lead to light emission and to develop high performance radical emitters with unprecedentedly short relaxation times and high photoluminescence quantum yields. To find systems with maximum performance, screening of differently substituted trityl radicals will be performed using quantum chemical calculations. Differently substituted radicals will be screened for fast decay rates using unrestricted simplified TD-DFT to identify systems with large oscillator strengths. Furthermore, we will determine the minimum energy of conical intersections between the D0 and D1-states to acquire information about non-radiative decay and transfer rates. For this purpose, we will developed an unrestricted version of the hole-hole-Tamm-Dancoff-approximated density functional theory method (hh-TDA).