Organotellurium Compounds as Supramolecular Building Blocks

With the support of the Macromolecular, Supramolecular and Nanochemistry (MSN) Program in the Division of Chemistry, and the Established Program to Stimulate Competitive Research (EPSCoR), at the National Science Foundation, Prof. Thomas Junk of the University of Louisiana at Lafayette and his collaborators plan to investigate the properties of novel compounds of the element tellurium (Te), which currently finds applications in modern devices such as solar cells. Tellurium compounds are able to spontaneously form complex structures resulting from the interaction of multiple molecules, a process called supramolecular self-assembly. This holds promise for the development of components for optical and electronic devices. Prof. Junk’s team plans to take on two challenges in order to realize the application potential: firstly, new and green methods will be developed to make such compounds. Secondly, advanced computation methods are planned to model the self-assembly process to rationally design materials with desirable properties. All participants, notably participating graduate and undergraduate students, will gain an improved understanding of supramolecular assemblies. The project is further expected to catalyze interdisciplinary collaborations within Louisiana and across EPSCoR jurisdictions. The project will focus on tellurazoles and tellurazines, selected for their high chemical stability. Such compounds are capable of forming strong secondary chalcogen bonding interactions (SBI’s), but the extent to which this happens strongly depends on substituents present in the molecules. The first step will be the development of improved synthetic strategies that permit more structural flexibility than currently feasible, notably by employing regioselective electrophilic tellurination. The second will be an ab initio modeling of SBI formation. The results will be benchmarked against a library of the prepared test substrates to provide a foundation for targeted syntheses. Collaborative research to establish organotellurium compounds as components in non-linear optical devices, sensors, redox catalysts, chelators and organic photoemitters is scheduled follow. An overarching vision of this project will be the integration of supramolecular chemistry into the research and teaching activities at this institution. 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.