苯胺基团对一类Pt(Ⅱ)磷光发光材料非辐射跃迁调控的理论研究  

Theoretical Study on Regulation of Aniline Moiety on Non-radiative Transition of a Kind of Pt(Ⅱ)Phosphorescent Materials

作　　者：康国俊[1] 李珂[1] 任雪峰[1] 唐洪渠 KANG Guo-Jun;LI Ke;REN Xue-Feng;TANG Hong-Qu(Low Carbon Energy Institute,School of Chemical Engineering&Technology,China University of Mining and Technology,Xuzhou,Jiangsu 221008,China)

机构地区：[1]中国矿业大学低碳能源研究院,化工学院,徐州221008

出　　处：《无机化学学报》2021年第3期569-576,共8页Chinese Journal of Inorganic Chemistry

基　　金：中央高校基金(No.2017XKQY065)资助。

摘　　要：采用密度泛函(DFT)和含时-密度泛函(TD-DFT)方法研究二苯胺基团对一类Pt(Ⅱ)配合物(M1~M3)光学性质的调控。通过与实验合成的分子对比,揭示苯胺基团取代位置和数量对电子结构和光学性质的调控规律。引入苯胺基团可有效地增大金属和配体的π共轭性。逐渐增多苯胺基团导致M3分子可以有效地增大吸收光谱的强度和金属到配体的电荷转移(MLCT)占比有利于金属对光的吸收和自旋轨道耦合。M1~M3的发射峰在602~630 nm,发射光谱归属为3MLCT和配体之间的电荷转移(3LLCT)。通过对非辐射跃迁过程,即T1(3MLCT)→TS→金属中心三重态3MC(d-d)的研究,发现当二苯胺取代基团引入位置可以有效地增大分子内空间位阻时,形成S0和T1的系间交叉MECP能量变得更高,从而抑制了非辐射的概率,有利于发光性能提高。A series of efficient red platinum-based emitter with functionalized diphenylamine moiety(M1-M3)were designed and investigated by density functional theory(DFT)and time-dependent DFT(TD-DFT).The effect of different substituent positions on the electronic structures and optical properties were fully explored by compared with the synthesized complex.The introduction of diphenylamine moiety could effectively strengthen theπ-conjugation interaction between the metal and ligand.By gradually increasing the amount of diphenylamine moiety,the intensities and the participation of metal-to-ligand charge-transfer(MLCT)for the absorption bands of M3 were enhanced,which are beneficial to collect light energy participation of metals and increase the spin-orbital coupling effect.M1~M3 exhibited red emission with the peak wavelengths at 602~630 nm.These emission spectra are mixtures of 3 MLCT and ligand to ligand charge-transfer(3 LLCT)character.The possible non-radiative process T1(3 MLCT)→TS→triplet metal-centered 3 MC(d-d)state were deeply investigated,and the results show that the possibility of the non-radiative process will decrease because the surface crossing at a minimum energy crossing point(MECP)between T1 and S0 state is difficult to populate when the functionalized diphenylamine moiety is useful to enhance steric hindrance.

关 键 词：密度泛函理论 激发态 非辐射跃迁过程 金属中心三重态 

分 类 号：O614.826[理学—无机化学]