Kim Mingi, Ryu Chan Hee, You Dong Kyun, Hong Ju Hyun, Lee Kang Mun
Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea.
ACS Omega. 2022 Jun 30;7(27):24027-24039. doi: 10.1021/acsomega.2c03344. eCollection 2022 Jul 12.
-Carboranyl compounds contain specific geometries, ranging from planar to orthogonally distorted biphenyl rings. Herein, 13 -carboranyl compounds, , were synthesized and fully characterized to determine the impact of structural formation of the aromatic group appended with the -carborane to estimate the efficiency of their radiative decay process. All the compounds exhibited significant intramolecular charge transfer (ICT)-based emission in the crystalline state at 298 K. Remarkably, increasing the distorted dihedral angles between biphenyl rings gradually decreased the emission efficiencies. Furthermore, their radiative decay constants decreased linearly with increasing dihedral angles, which demonstrated the inversely proportional relationship between these two factors. These findings distinctly suggest that the planar or distorted geometry of substituted aryl groups can strongly affect the efficiency of the ICT-based radiative process in -carboranyl luminophores.
-碳硼烷化合物具有特定的几何结构，范围从平面到正交扭曲的联苯环。在此，合成并全面表征了13种碳硼烷化合物，以确定连接碳硼烷的芳基结构形成的影响，从而评估其辐射衰变过程的效率。所有化合物在298K的结晶状态下均表现出基于分子内电荷转移（ICT）的显著发射。值得注意的是，联苯环之间扭曲二面角的增加逐渐降低了发射效率。此外，它们的辐射衰变常数随二面角的增加呈线性下降，这表明这两个因素之间成反比关系。这些发现清楚地表明，取代芳基的平面或扭曲几何结构会强烈影响碳硼烷发光体中基于ICT的辐射过程的效率。
