Synthesis of Main Group Compounds and Materials with Novel Structures and Optoelectronic Properties

在凯斯西储大学化学系化学合成项目的支持下，John Protasiewicz教授和他的学生们正在制备含有P= c的扩展pi电子系统的化合物。P=C单元允许调整材料的光学和电子特性，以最大限度地提高材料的性能。这些研究的动机是需要经济的手段来制造高效的照明和显示。利用廉价和丰富的元素以及尽量减少浪费和有毒副产品形成的方法特别有吸引力。该项目设想制备低成本/轻质/可加工塑料和与发光技术相关的材料。例子包括聚合物、分子电子学、发光二极管、光伏和柔性电子学。作为这项研究计划的一部分，接受培训和教育的学生正准备进入明天的工业和教育领域的熟练劳动力。除了与先进制造业相关的更广泛的技术影响外，Protasiewicz教授还将共同组织和开展旨在提高研究生和教师对心理健康问题认识的项目。将合成反应性主基团体系并对其光物理性质进行研究，以推进和开创主基团光物理化学的新范式。这项工作探索了几个相互关联的研究线索，灵感来自先前对发光1,3-苯并膦孔和1,3-苯并膦孔的研究。将制备一类具有P=C键的新型光致发光化合物（磷-azulenes），以显示S2（而不是S1）激发态的荧光，从而打破Kasha规则。抗卡沙化合物是罕见的，具有理想的光物理性质。n-杂环碳烯和荧光仲胺之间的非常规氢键将被用于开发二碳烯的超分子化学，二碳烯可以与含有两个NH官能团的荧光团发生氢键，这将为开发可作为特定应用的荧光传感器的材料提供新的机会。先前的研究还发现了一种不寻常的反应，将邻膦酚转化为苯二氮磷。这个过程包括去除6个氢原子，形成新的PP和PO键。这一过程将扩展到其他类型的键，并尝试使该过程具有催化作用。在这项研究中开发的无金属系统摆脱了以前报道的基于昂贵和/或有毒过渡金属的策略，而集中于毒性较小和土壤丰富的元素。结合起来，这些努力旨在推进和展示主要群体元素可以为光电和结构材料的更大领域提供的优势。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Synthesis program of the Division of Chemistry, Professor John Protasiewicz and his students at the Department of Chemistry at Case Western Reserve University are preparing compounds with P=C-containing extended pi-electron systems. The inclusion of P=C units permits the optical and electronic properties of the material to be tuned in order to maximize the behavior of the material. A motivation for these studies is a need for economical means to manufacture highly efficient lighting and displays. Methods that utilize inexpensive and abundant elements and ones that minimize the formation of wasteful and toxic byproducts are especially attractive. This project envisions the preparation of low cost/lightweight/processable plastics and materials related to light emitting technology. Examples, include polymers, molecular electronics, light emitting diodes, photovoltaics, and flexible electronics. The students trained and educated as part of this research program are being prepared to enter tomorrow's skilled workforce in industry and education. In addition to the technical broader impacts related to advanced manufacturing, Professor Protasiewicz will co-organize and run programs directed at raising awareness of mental health issues among graduate students and faculty.Reactive main group systems will be synthesized and their photophysical properties interrogated to advance and create new paradigms in main group photophysical chemistry. This work explores several interconnected research threads, inspired from previous studies on luminescent 1,3-benzoxaphospholes and 1,3-benzazaphospholes. A new class of photoluminescent compounds (phospha-azulenes) bearing P=C bonds will be prepared to display fluorescence from the S2 (not S1) excited state, thus breaking Kasha's rule. Anti-Kasha compounds are rare and have desirable photophysical properties. Unconventional hydrogen bonding between N-heterocyclic carbenes and fluorescent secondary amines will be exploited to develop the supramolecular chemistry of dicarbenes that can undergo hydrogen bonding to a fluorophores containing two NH functional groups, which will offer new opportunities to develop materials that could act as turn-on fluorescent sensors for select applications. Previous studies also uncovered an unusual reaction that converts ortho-phosphinophenol to benzodioxaphosphole. This process involves removing 6 hydrogen atoms and making new PP and PO bonds. This process will be extended to other types of bonds and and attempts will be made to make the process catalytic. The metal-free systems to be developed in this research move away from previously reported strategies based on expensive and/or toxic transition metals and concentrates on elements that are less toxic and more earth abundant. Combined, these efforts aim to advance and showcase the advantages that main group elements can offer to the greater field of optoelectronic and structural materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.