Wang Junhao, Zakrzewski Jakub J, Heczko Michal, Zychowicz Mikolaj, Nakagawa Kosuke, Nakabayashi Koji, Sieklucka Barbara, Chorazy Szymon, Ohkoshi Shin-Ichi
Department of Chemistry, School of Science , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 , Japan.
Faculty of Chemistry , Jagiellonian University , Gronostajowa 2 , 30-387 Kraków , Poland.
J Am Chem Soc. 2020 Feb 26;142(8):3970-3979. doi: 10.1021/jacs.9b13147. Epub 2020 Feb 12.
Lanthanide(III)-based coordination complexes have been explored as a source of bifunctional molecular materials combining Single-Molecule Magnet (SMM) behavior with visible-to-near-infrared photoluminescence. In pursuit of more advanced multifunctionality, the next target is to functionalize crystalline solids based on emissive molecular nanomagnets toward high proton conductivity and an efficient luminescent thermometric effect. Here, a unique multifunctional molecule-based material, (HO)(H)[Yb(hmpa)][Co(CN)]·0.2HO (, hmpa = hexamethylphosphoramide), composed of molecular {YbCo} anions noncovalently bonded to acidic HO and H ions, is reported. The resulting Yb complexes present a slow magnetic relaxation below 6 K and room temperature NIR 4f-centered photoluminescence sensitized by [Co(CN)] ions. The microporous framework, built on these emissive magnetic molecules, exhibits a high proton conductivity of the H-hopping mechanism reaching σ of 1.7 × 10 S·cm at 97% relative humidity, which classifies as a superionic conductor. Moreover, the emission pattern is strongly temperature-dependent which was utilized in achieving a highly sensitive single-center luminescent thermometer with a relative thermal sensitivity, > 1% K in the 50-175 K range. This work shows an unprecedented combination of magnetic, optical, and electrical functionalities in a single phase working as a proton conductive NIR-emissive thermometer based on Single-Molecule Magnets.
基于镧系元素（III）的配位络合物已被探索作为一种双功能分子材料的来源，该材料将单分子磁体（SMM）行为与可见光到近红外光致发光相结合。为了追求更先进的多功能性，下一个目标是基于发光分子纳米磁体对晶体固体进行功能化，以实现高质子传导率和高效的发光测温效应。在此，报道了一种独特的基于多功能分子的材料，(HO)(H)[Yb(hmpa)][Co(CN)]·0.2HO（，hmpa = 六甲基磷酰胺），它由与酸性HO和H离子非共价键合的分子{YbCo}阴离子组成。所得的Yb络合物在6 K以下呈现缓慢的磁弛豫，并且在室温下具有由[Co(CN)]离子敏化的近红外4f中心光致发光。基于这些发光磁性分子构建的微孔框架在97%相对湿度下表现出通过H跳跃机制实现的高质子传导率，达到σ为1.7×10 S·cm，这使其归类为超离子导体。此外，发射模式强烈依赖于温度，这被用于实现一种高灵敏度的单中心发光温度计，在50 - 175 K范围内相对热灵敏度>1% K。这项工作展示了在基于单分子磁体的质子传导近红外发射温度计的单相中前所未有的磁、光和电功能的组合。
