Mandapati Pavan, Braun Jason D, Lozada Issiah B, Williams J A Gareth, Herbert David E
Department of Chemistry and the Manitoba Institute for Materials, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba, R3T 2N2, Canada.
Department of Chemistry, Durham University, Durham, DH1 3LE, U.K.
Inorg Chem. 2020 Sep 8;59(17):12504-12517. doi: 10.1021/acs.inorgchem.0c01584. Epub 2020 Aug 18.
A synthetic methodology for accessing narrow-band, deep-red phosphorescence from mononuclear Pt(II) complexes is presented. These charge-neutral complexes have the general structure ()PtCl, in which the Pt(II) centers are supported by benzannulated diarylamido ligand scaffolds bearing substituted quinolinyl and/or phenanthridinyl arms. Emission maxima ranging from 683 to 745 nm are observed, with lifetimes spanning from 850 to 4500 ns. In contrast to the corresponding proligands, benzannulation is found to counterintuitively but markedly blue-shift emission from metal complexes with differing degrees of ligand benzannulation but similar substitution patterns. This effect can be further tuned by incorporation of electron-releasing (Me, Bu) or electron-withdrawing (CF) substituents in either the phenanthridine 2-position or quinoline 6-position. Compared with symmetric (quinoline) and (phenanthridine) architectures, "mixed" ligands incorporating one quinoline and one phenanthridine unit present a degree of charge transfer between the -heterocyclic arms that is more pronounced in the proligands than in the Pt(II) complexes. The impact of benzannulation and ring-substitution on the structure and photophysical properties of both the proligands and their deep-red emitting Pt(II) complexes is discussed.
本文介绍了一种用于从单核Pt(II)配合物获得窄带深红色磷光的合成方法。这些电中性配合物具有通式()PtCl，其中Pt(II)中心由带有取代喹啉基和/或菲啶基臂的苯并稠合二芳基酰胺配体支架支撑。观察到发射最大值在683至745nm范围内，寿命在850至4500ns之间。与相应的前体配体相反，发现苯并稠合会使具有不同程度配体苯并稠合但取代模式相似的金属配合物的发射发生反直觉但明显的蓝移。通过在菲啶2位或喹啉6位引入供电子（Me、Bu）或吸电子（CF）取代基，可以进一步调节这种效应。与对称（喹啉）和（菲啶）结构相比，包含一个喹啉和一个菲啶单元的“混合”配体在杂环臂之间呈现出一定程度的电荷转移，这在前体配体中比在Pt(II)配合物中更为明显。讨论了苯并稠合和环取代对前体配体及其深红色发射Pt(II)配合物的结构和光物理性质的影响。
