Abstract
Herein we show that cyclometalated, square planar Pt(II) complexes can be tuned to achieve deep-blue phosphorescent emitters. For this purpose, the introduction of an electron-donating moiety on two different bidentate NˆN and NˆO fluorine-free luminophores, namely 2-(1H-tetrazol-5-yl)pyridine and picolinic acid, was carried out. The remaining two coordination sites of the Pt(II) metal center were filled by a sterically demanding cyclometallating unit, namely a tertiary phosphite CˆP ligand. This ancillary ligand avoids aggregation and provides high solubility in organic solvents. Based on this approach, we were able to blue-shift the emission of the complexes down to 411 nm, and to achieve a maximal photoluminescence quantum yield of 56% in the solid state.
在这里,我们展示了环金属化的、平面四方形的Pt(II)配合物可以被调节以实现深蓝色磷光发射体。为此,对两种不含氟的双齿NˆN和NˆO荧光团的引入了一个给电子基团,即2-(1H-四唑-5-基)吡啶和吡啶甲酸。Pt(II)金属中心的剩余两个配位位点由一个立体位阻大的环金属化单元填充,即三膦基CˆP配体。这个辅助配体避免了聚集并在有机溶剂中提供高溶解度。基于这种方法,我们能够将配合物的发射向蓝色移动到411纳米,并在固态中实现56%的最大光致发光量子产率。