Collaborative Research: Hydrazone-Based Solid-State Light Emitters

用高效的固态照明设备取代广泛使用的、效率极低的白炽灯泡和紧凑型荧光灯，可以大幅降低我们的国内总能耗和二氧化碳排放量。 该项目正在开发两类固态发光器，以解决与基于有机材料的固态发光器相关的多个缺点。为了实现这一目标，研究小组正在利用实验和计算技术推进对基于腙的固态发光体的分子水平理解。两名首席研究员积极参与教育和推广活动，为NH和VT的贫困大学预科学生提供有意义的学习机会，留住已经在其机构化学管道中的学生，并通过非正式的科学教育活动吸引公众。这些研究和推广活动得到了材料研究部的固态和材料化学计划以及化学部的大分子，超分子和纳米化学计划的支持。技术摘要这个合作研究项目采用有机和物理化学的工具来推进对基于腙的材料的两个显着的物理化学性质的基本理解，即，聚集诱导发射（AIE）和宽的荧光带宽。BF 2-腙（BODIHY）染料已经在固态光（SSL）发射体领域中带来了范式转变，因为这些分子在固态下表现出AIE，尽管存在似乎有利于淬灭的分子间π-π相互作用。本文研究的另一类基于腙的材料，即三唑并吡啶（TOP）盐，是具有大斯托克斯位移和宽荧光带宽的蓝光发射材料，这两种特性在先进能源应用中具有巨大的潜在价值。达特茅斯学院的研究小组使用一种有效的合成方法来制备不同的BODIHY和TOP染料库，用于结构-性质分析。这些BODIHY和TOP染料的物理化学性质在溶液和固态中都被广泛表征，主要使用电子吸收和荧光光谱。此外，佛蒙特大学的研究小组利用电子结构计算来阐明基于腙的染料的物理机制，并对其荧光特性进行先验预测，以加快发现和开发新的高效固态发射器，这些发射器可以轻松部署并集成到SSL应用中。最终，该项目在有机和物理化学领域创造了新的基础知识，这对材料和超分子化学社区具有重要价值。

Non-Technical AbstractReplacing widely used and highly inefficient incandescent bulbs and compact fluorescent lamps with efficient solid-state light devices can drastically reduce our total domestic energy consumption and CO2 production. This project is developing two classes of solid-state light emitters to address multiple drawbacks associated with organic material-based solid-state light emitters. To accomplish this goal, the research team is advancing the molecular level understanding of hydrazone-based solid-state light emitters using experimental and computational techniques. The two lead investigators are actively involved in educational and outreach activities that provide meaningful learning opportunities for underprivileged pre-college students in NH and VT, retain students already in the chemistry pipeline at their institutions, and engage the general public through informal science education activities. These research and outreach activities are supported by the Solid State and Materials Chemistry program in the Division of Materials Research as well as the Marcromolecular, Supramolecular, and Nanochemistry program in the Division of Chemistry.Technical AbstractThis collaborative research project employs the tools of organic and physical chemistry to advance fundamental understanding of two remarkable photophysical properties of hydrazone-based materials, namely, aggregation induced emission (AIE) and broad fluorescent bandwidths. BF2-hydrazone (BODIHY) dyes have brought about a paradigm shift in the field of solid-state light (SSL) emitters as these molecules exhibit AIE in the solid-state despite the presence of intermolecular pi-pi interactions that would seem to favor quenching. The other family of hydrazone-based materials investigated here, triazolopyridinium (TOP) salts, are blue light emitting materials with large Stokes shifts and broad fluorescent bandwidths, two properties of great potential value in advanced energy applications. The research team at Dartmouth College uses an efficient synthetic approach to prepare diverse libraries of BODIHY and TOP dyes for structure-property analyses. The photophysical properties of these BODIHY and TOP dyes are extensively characterized, both in solution and the solid-state, primarily using electronic absorption and fluorescence spectroscopies. In addition, the research team at the University of Vermont utilizes electronic structure calculations to elucidate the photophysical mechanisms of hydrazone-based dyes, and make a priori predictions regarding their fluorescent properties to expedite the discovery and development of new and efficient solid-state emitters that can be easily deployed and integrated into SSL applications. Ultimately, this project creates new, fundamental knowledge in the fields of organic and physical chemistry, which is of significant value to the materials and supramolecular chemistry communities.