Collaborative Research: Multifunctional Cross-conjugated Organic Electronic Materials.

在化学系大分子、超分子和纳米化学项目的支持下，波士顿大学的Malika Jeffries-El博士和北乔治亚大学的Aimée Tomlinson博士正在开发可调有机半导体。这些碳基材料将传统无机半导体的光学和电子性能与聚合物的加工性结合在一起。因此，它们具有广泛的应用前景，例如化学/光学传感器、显示器和太阳能电池。在这个项目中，一种具有十字形基序的新型分子的基本化学结构将被系统地修改，以适应由此产生的电子性质。首先将利用计算方法来确定最有希望的合成和表征候选对象。然后将使用合成有机化学通过一系列成熟的转化来制备这些主题。最后，将使用各种复杂的光谱技术对所得到的系统进行表征，最后是器件的制造。这项研究将产生的结构-性质相关性有可能促进有机电子领域的基础化学知识。该奖项为材料和计算化学方面的本科生和研究生培训提供了新的机会，重点是低收入和/或第一代学生。此外，还将启动一项新的波士顿大学生命科学包容性卓越计划，旨在提高未被充分代表的群体获得STEM学位的机会。这项研究将结合实验和理论方法开发基于一类独特化合物的新材料，交叉共轭苯并[1，2-d：4，5-d‘]双恶唑(BBO)S(BBO)。交叉共轭对于开发有机半导体特别有用，因为两条垂直共轭路径的排列导致前沿分子轨道的空间分离。其结果是，HOMO(最高占据分子轨道)和LUMO(最低未占据分子轨道)可以自主修正。各种(杂环)芳环沿BBO部分轴线的进一步战略定位有望通过扩展pi-键网络和通过芳环的诱导效应来实现系统的光学和电学性质的调谐。通过这种方式，有可能定制用于特定应用的交叉共轭BBOS，包括用作有机光伏中的非富勒烯受体，以及用作有机发光二极管(LED)的蓝色发光体和宽带隙主机。这项工作将使用一个反馈回路来完成，该回路结合了理论、合成、光谱学和器件制造来识别和产生新材料。这种迭代方法应允许在知情的情况下访问目标BBO。此外，计划中的结构-性质研究有可能促进具有可调和可预测的光学和电子性能的新型共轭材料的合理设计。该奖项还将为本科生和研究生在材料和计算化学方面的培训提供新的机会，重点是低收入和/或第一代学生。PIS将通过参与各自校园的各种活动来招收这些学生。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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 Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry, Drs. Malika Jeffries-EL of Boston University and Aimée Tomlinson of the University of North Georgia are developing tunable organic semiconductors. These carbon-based materials combine the optical and electronic properties of conventional inorganic semiconductors with the processibility of polymers. Thus, they can potentially be used in a wide range of applications such as chemical/optical sensors, displays, and solar cells. In this project, the basic chemical structure of a novel molecule with a cross-like motif will be systematically modified to tailor the resulting electronic properties. Computational methods will first be utilized in order to identify the most promising candidates for synthesis and characterization. Synthetic organic chemistry will then be used to prepare these motifs through a series of well-established transformations. Finally, the resulting systems will be characterized using a variety of sophisticated spectroscopic techniques, concluding with the fabrication of devices. The structure-property correlations that will result from this research have the potential to advance fundamental chemistry knowledge in the field of organic electronics. This award provides new opportunities for undergraduate and graduate student training in materials and computational chemistry, with an emphasis on low-income and/or first-generation students. Additionally, a new Boston University Life Sciences Inclusive Excellence Initiative will be launched which seeks to increase STEM degree attainment for underrepresented groups. This program will provide training of faculty in inclusive excellence, with the aim of boosting retention in STEM majors, and increasing longitudinal outcomes, such as entry into post-secondary programs or employment.This research will combine experimental and theoretical approaches to develop new materials based on a unique class of compounds, cross-conjugated benzo[1,2-d:4,5-d’]bisoxazoles (BBO)s. Cross-conjugation is especially useful for developing organic semiconductors as the arrangement of two orthogonal conjugation paths leads to spatial segregation of the frontier molecular orbitals. As a result, the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) can be modified autonomously. Further strategic positioning of the various (hetero)aromatic rings along the axes of the BBO moiety is expected to enable tuning of the optical and electronic properties of the system through extension of the pi-bond network and through inductive effects from the aryl rings. In this way, it may be possible to tailor cross-conjugated BBOs for use in specific applications including as non-fullerene acceptors in organic photovoltaics, and as blue light-emitters and wide band gap hosts for organic light-emitting diodes (LEDs). This work will be accomplished using a feedback loop that combines theory, synthesis, spectroscopy, and device fabrication to identify and generate new materials. This iterative approach should allow for well-informed access to the target BBOs. Furthermore, the planned structure-property studies have the potential to advance the rational design of new conjugated materials with tunable and predictable optical and electronic properties. This award also will provide new opportunities for undergraduate and graduate student training in materials and computational chemistry, with an emphasis on low-income and/or first-generation students. The PIs will recruit such students through their participation in various activities on their respective campuses.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.