Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan.
Dalton Trans. 2012 Jul 21;41(27):8379-89. doi: 10.1039/c2dt30071k. Epub 2012 May 28.
We have synthesized a series of platinum (Pt) complexes having a rod-like ligand: 'Pt(F(2)PPy)acac', 'Pt(12F(2)PPy)acac', and 'Pt(12F(2)PPyO4)acac'. The crystal form of Pt(12F(2)PPy)acac was successfully determined to be triclinic by single-crystal X-ray structural analysis. The molecules were parallelly aligned in the unit cell. Monomer and excimer emissions of Pt(12F(2)PPy)acac were observed in hexane solution, poly(methyl methacrylate) film, and various nematic LCs. Homogeneous LC cells with the Pt complex/LC mixtures exhibited polarized optical emission resulting from monomer and excimer states. The PL intensity perpendicular to the orientation direction was higher than the parallel one in the whole wavelength region of the Pt complex and the polarization ratio of the excimer was higher than that of the monomer. The polarization ratios of the excimers were estimated to be 1.4-2.5 in nematic LC at room temperature, and decreased gradually with increasing temperature. The polarization ratios of Pt(12F(2)PPyO4)acac were higher than those of Pt(F(2)PPy)acac and Pt(12F(2)PPy)acac in all the LCs.
我们合成了一系列具有棒状配体的铂（Pt）配合物：'Pt(F(2)PPy)acac'、'Pt(12F(2)PPy)acac'和'Pt(12F(2)PPyO4)acac'。通过单晶 X 射线结构分析成功确定了 Pt(12F(2)PPy)acac 的晶体形式为三斜晶系。分子在晶胞中平行排列。在己烷溶液、聚甲基丙烯酸甲酯薄膜和各种向列液晶中观察到 Pt(12F(2)PPy)acac 的单体和激基复合物发射。具有 Pt 配合物/LC 混合物的均匀 LC 池表现出源于单体和激基复合物态的偏振光学发射。在 Pt 配合物的整个波长区域内，垂直于取向方向的 PL 强度高于平行于取向方向的强度，并且激基复合物的偏振比高于单体的偏振比。在室温下的向列液晶中，激基复合物的偏振比估计为 1.4-2.5，并且随着温度的升高逐渐降低。在所有液晶中，Pt(12F(2)PPyO4)acac 的偏振比都高于 Pt(F(2)PPy)acac 和 Pt(12F(2)PPy)acac。
