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Kennesaw州立大学化学和生物化学系教员Michael Stollenz教授的项目。Stollenz小组正在探索包含单个金属原子的特定排列的新型分子。这些分子是高度发光的，它们有可能用作分子导线。几十年来，分子线一直让科学家们着迷，因为它们是在亚微观尺度上建造微型化电子设备的重要组成部分。发光的铜、银和金的多核配合物在这方面特别有兴趣，因为它们也可以应用于分子/有机发光二极管(OLED)。为了建造这种性质的分子线，需要合成方法来产生包含单个金属原子的特定排列的新分子。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导电分子线圈的大量弯曲的排列。这种嵌入在电子电路中的分子线圈的长期前景是将它们用作微小的电磁体，可以集成到纳米机器和其他纳米级的电子设备中。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。如果这些设备是发光的，就可以通过荧光成像来跟踪它们的路径。这项工作的更广泛影响还包括对肯纳索州立大学人数众多的未被充分代表的群体的本科生和硕士学生的指导和培训。该研究计划专注于开发和实施多核硬币金属阵列的新策略，这些金属阵列既可以作为潜在的导电分子线圈，也可以作为分子/有机发光二极管(OLED)。基本的合成方法为控制线性簇合物的聚集提供了基本的途径，并提供了对多核络合物阵列的配位化学的深入了解。具体地说，一个能够容纳至少四个以线性方式排列的铜或银中心的新的双(酰胺)配体的库正在创建中。在阵列中掺入铜(I)离子是通过使用清洁的有机金属铜(I)源--介晶基铜来完成的。得到的线状簇合物既可以是同质络合物，也可以是保留均三甲基的络合物。末端带有额外N-供体基团的双(酰胺)配体被AuCl络合物片段选择性地保护。这些迄今未知的数字金属配体被用作新的线状或束状同核金或异双金属金/铜簇合物的构建块，作为有前途的发光材料。最后，合成了新的双(酰胺)锂配合物，并研究了它们在溶液中的行为。此外，该课程还为本科生和研究生提供关于合成、表征技术(结晶学和光谱学)、口头演示技能、科学写作、实验室安全和数据管理的深入培训和指导。这些措施为学生在科学或工业领域实现他们雄心勃勃的职业目标做好了准备。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。

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.