RUI: Highly Luminescent Multinuclear Coinage Metal Arrays with a Twist: A New Approach to Design Light-Emitting Molecular Wires and Coils

化学部的化学合成计划支持肯尼索州立大学化学和生物化学系的教员Michael Stollenz教授的项目。Stollenz小组正在探索含有单个金属原子特定排列的新型分子。这些分子是高度发光的，它们有可能作为分子导线。几十年来，分子导线一直吸引着科学家，因为它们是在亚微观尺度上构建微型电子设备的重要组成部分。在这方面，铜、银和金的发光多核络合物特别令人感兴趣，因为它们也可以应用于分子/有机发光二极管（OLED）。为了构建这种性质的分子线，需要合成方法，可以产生包含单个金属原子特定排列的新分子。考虑到这一点，Stollenz教授和他的团队正在努力开发新的方法，不仅可以生产铜、银和金离子的严格线性阵列，而且还可以生产用于传导分子线圈的基本弯曲的排列。这种嵌入电子电路中的分子线圈的长期前景是利用它们作为微小的电磁铁，可以集成在纳米机器和其他纳米级电子设备中。这样的设备可以反过来应用于在人体内输送药物的纳米机器人。如果这些装置是发光的，则它们的路径可以通过荧光成像来跟踪。这项工作的更广泛影响还包括指导和培训来自肯尼索州立大学的代表性不足群体的本科生和硕士生。这项研究计划的重点是开发和实施新的战略，多核钴金属阵列，既作为潜在的导电分子线圈，也作为分子/有机发光二极管（OLED）。基本的合成方法提供了一个基本的方法来控制线性簇组装体的聚集，并提供了一个深刻的洞察到一般的多核络合物阵列的配位化学。具体地，正在创建能够容纳以线性方式排列的至少四个铜或银中心的新的双（脒）配体库。Cu（I）离子在阵列中的掺入通过采用清洁的有机金属Cu（I）源（mesitylcopper）来完成。所得的线性簇组装体可以是均配络合物或保留异亚丙基甲苯基团的络合物。双（脒）配体与额外的终端N-供体基团的AuCl复合物片段的选择性保护。这些迄今未知的digold-metalloligands被用作新的线性或成束的homoboxy金或heteroboxy金/铜簇组装体作为有前途的发光材料的构建块。最后，合成了新的双脒基锂配合物，并研究了它们在溶液中的行为。此外，该计划还为本科生和研究生提供了合成，表征技术（晶体学和光谱学），口头陈述技能，科学写作，实验室安全和数据管理方面的深入培训和指导。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Chemical Synthesis Program of the Chemistry Division supports the project by Professor Michael Stollenz, a faculty member in the Department of Chemistry and Biochemistry at Kennesaw State University. The Stollenz Group is exploring novel molecules that contain specific arrangements of individual metal atoms. The molecules are highly luminescent, and they have the potential to serve as molecular wires. Molecular wires have fascinated scientists for decades because they are an essential component of building miniaturized electron devices on the submicroscopic scale. Luminescent, multinuclear complexes of copper, silver, and gold are of particular interest in this regard, since they can also be applied in molecular/organic light-emitting diodes (OLEDs). To build molecular wires of this nature, synthetic methodologies are needed that can produce new molecules that contain specific arrangements of the individual metal atoms. With this in mind, Professor Stollenz and his group are working to develop new methodology for producing not only strictly linear arrays of copper, silver, and gold ions, but also arrangements that are substantially bent for use in conducting molecular coils. A long-term prospect for such molecular coils, embedded in electronic circuits, is to utilize them as tiny electromagnets that can be integrated in nanomachines and other nanoscaled electronic devices. Such devices can in turn be applied in nanorobots that deliver drugs inside a human body. If these devices are luminescent, their path can be followed by fluorescence imaging. The Broader Impacts of the work also includes the mentoring and training of undergraduate and master students from the significant population of underrepresented groups at Kennesaw State University.This research program focuses on the development and implementation of new strategies to multinuclear coinage metal arrays that both serve as potentially conducting molecular coils and as molecular/organic light-emitting diodes (OLEDs). The underlying synthetic methods give a fundamental approach to control aggregation of linear cluster assemblies and provide a deep insight into the coordination chemistry of multinuclear complex arrays in general. Specifically, a library of new bis(amidine) ligands that are capable of accommodating at least four copper or silver centers, arranged in a linear fashion, is being created. The incorporation of Cu(I) ions in the arrays is accomplished by employing a clean organometallic Cu(I) source, mesitylcopper. The resulting linear cluster assemblies can either be homoleptic complexes or complexes that retain the mesityl groups. Bis(amidine) ligands with additional terminal N-donor groups are selectively protected by AuCl complex fragments. These heretofore unknown digold-metalloligands are utilized as building blocks for new linear or bundled homonuclear gold or heterobimetallic gold/copper cluster assemblies as promising luminescent materials. Finally, new bis(amidinato)lithium complexes are synthesized and their behavior in solution is investigated. Furthermore, this program provides an in-depth training and mentoring of undergraduate and graduate students in synthesis, characterization techniques (crystallography and spectroscopy), oral presentation skills, scientific writing, laboratory safety, and data management. These measures prepare students to achieve their ambitious career goals in science or industry.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.