Encouraging pi-electron delocalization through boron-based heteroaromatic subunits

在这个由化学部化学结构、动态和机制B项目资助的项目中，约翰霍普金斯大学化学系的John D Tovar教授将开发新型硼基分子材料，这种材料具有类似于传统无机半导体的特性。这些有机分子已成为当代有机电子学的有吸引力的组件，其应用跨越阴离子传感，非线性光学和发光器件。这些领域的学生将在未来的商业和学术发展中发挥关键作用。这个特殊研究项目的一个不同寻常和吸引人的因素是它将为本科生和研究生提供的培训环境。在获得特定π共轭材料所需的合成有机化学培训之外，学生将接触到光电表征方法，并将作为合作努力的亲密参与者来制造新器件。在这个项目的框架下，PI将通过继续支持研究生和本科生的研究机会，帮助增加妇女和代表性不足的少数民族对高级学位课程的参与。硼基pi-电子材料已成为当代有机电子学中有吸引力的元件。将偶联有机硼烷纳入有机电子材料的典型结构基序包括三芳基硼烷以及具有芳香（如带正式电荷的氮杂环和硼二苯环）和反芳香（如硼环）特征的含硼环烯。在这个列表中缺少正式中性的硼芳香族，例如那些以borepin环为例的。将borepin纳入有机电子支架的主要科学动机是了解弱borepin芳香性如何影响pi电子离域和极化的基本问题，因为这些分子有望保持高度的“环多烯”特征，同时仍提供一定程度的芳香共振稳定能量。为了了解这些独特的偶联特性如何被用于新材料设计，将研究具有不同程度的分子内和分子间电子离域的新borepin结构。这些borepin支架将通过电子方式进行充分表征，以了解其新颖的芳香性和极化性，并将其转化为探索各种有机电子应用的合作努力。

In this project funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor John D Tovar of the Department of Chemistry at Johns Hopkins University will develop new classes of boron-based molecular materials that have properties akin to traditional inorganic semiconductors. These organic molecules have emerged as attractive components for contemporary organic electronics, with applications spanning anion sensing, non-linear optics and light-emitting devices. Students in these areas will play critical roles in the future developments both on the commercial and academic fronts. One unusual and attractive element of this particular research program is the training environment it will offer to undergraduate and graduate students. Outside of the training in synthetic organic chemistry requisite for obtaining specific pi-conjugated materials, students will be exposed to optoelectronic characterization methods and will serve as intimate participants in collaborative efforts to make new devices. Under the umbrella of this project, the PI will help to increase participation of women and underrepresented minorities in advanced degree programs through continued support of research opportunities at the graduate and undergraduate level.Boron-based pi-electron materials have emerged as attractive components for contemporary organic electronics. Typical structural motifs through which pi-conjugated organoboranes can be included into organic electronic materials consist of triarylboranes as well as boron-containing annulenes with aromatic (such as formally charged azaborine and boratabenzene rings) and antiaromatic (such as borole rings) character. Lacking on this list are formally neutral boron aromatics such as those exemplified by the borepin ring. A primary scientific motivation for borepin inclusion into organic electronic scaffolds is to understand fundamental issues about how the weak borepin aromaticity would influence pi-electron delocalization and polarization given that these molecules would be expected to maintain high degrees of "cyclic polyene" character yet still provide some degree of aromatic resonance stabilization energy. To understand how these unique conjugation features might be exploited for new materials designs, new borepin architectures with varying degrees of intra- and inter-molecular electronic delocalization will be studied. These borepin scaffolds will be fully characterized electronically to understand their novel aromaticities and polarizabilities, and they will be transitioned into collaborative efforts to explore a variety of organic electronics applications.