Crystal Engineering of Vapochromic Porous Crystals Composed of Pt(II)-Diimine Luminophores for Vapor-History Sensors
作者:Yasuhiro Shigeta、Atsushi Kobayashi、Masaki Yoshida、Masako Kato
DOI:10.1021/acs.cgd.8b00130
日期:2018.6.6
A novel Pt(II) diimine complex, [Pt(CN)2(H2dpcpbpy)] (1, H2dpcpbpy = 4,4′-di(p-carboxyphenyl)-2,2′-bipyridine), was synthesized, and its vapochromic behavior was investigated. The yellow amorphous form of 1, 1-Ya, transformed into the porous orange crystalline form, 1-Oc, upon exposure to ethanol vapor. This behavior is similar to that of the previously reported complex, [Pt(CN)2(H2dcphen)] (2, H2dcphen = 4,7-dicarboxy-1,10-phenanthroline). X-ray diffraction study showed that 1-Oc possessed similar but larger porous channels (14.3 × 8.6 Å) compared to the red crystalline form of 2, 2-Rc (6.4 × 6.8 Å). Although the porous structure of 2-Rc was retained after vapor desorption, that of 1-Oc collapsed to form the orange amorphous solid, 1-Oa. However, the orange color was unchanged in this process. The initial color was recovered by grinding 1-Oa and 2-Rc. These vapor-writing and grinding-erasing functions can be applied to both in situ vapor sensing and vapor-history sensing, i.e., sensors that can memorize the existence of previous vapors. A notable difference was observed for humid air sensitivity; the orange emission of 1-Oa was largely unaffected upon exposure to humid air, whereas the red emission of 2-Rc was significantly affected. The lesser sensitivity of 1-Oa toward humidity is important for stable vapor-history sensor applications.
合成了一种新型铂(II)二亚胺配合物[Pt(CN)2(H2dpcpbpy)](1, H2dpcpbpy = 4,4′-二(对羧基苯基)-2,2′-联吡啶),并对其汽相行为进行了研究。1 的黄色无定形形式(1-Ya)在暴露于乙醇蒸汽后转变为多孔的橙色晶体形式(1-Oc)。这种行为与之前报道的复合物 [Pt(CN)2(H2dcphen)](2,H2dcphen = 4,7-二羧基-1,10-菲罗啉)相似。X 射线衍射研究表明,1-Oc 具有类似但更大的多孔通道(14.3 × 8.6 Å),而 2-Rc 的红色结晶形式则为 6.4 × 6.8 Å。虽然 2-Rc 的多孔结构在蒸气解吸后得以保留,但 1-Oc 的多孔结构却坍塌形成了橙色的无定形固体 1-Oa。但在此过程中,橙色并没有改变。通过研磨 1-Oa 和 2-Rc 可以恢复最初的颜色。这些蒸汽写入和研磨消除功能既可应用于原位蒸汽传感,也可应用于蒸汽历史传感,即能够记忆之前存在的蒸汽的传感器。在对潮湿空气的敏感性方面,我们观察到了明显的差异;暴露在潮湿空气中时,1-Oa 的橙色发射基本不受影响,而 2-Rc 的红色发射则受到很大影响。1-Oa 对湿度的敏感性较低,这对稳定蒸汽历史传感器的应用非常重要。