This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports Professor Zhiping Zheng at the University of Arizona to develop polymer hybrid materials featuring transition metal chalcogenide clusters as nanoscopic building blocks. Structurally altered well-defined cluster isomers will be used as monomers and initiators for controlled radical polymerization, as reagents for coupling with conjugated organic monomers, or as labile starting materials used in ligand exchange reactions for desired polymeric/dendritic ligands. Through the use of these designed cluster isomers, cluster-polymer hybrids with distinct and tunable molecular composition, structure, and properties are envisioned. This research addresses fundamental questions as to how the structures and functions of the cluster building blocks, together with those of the polymeric components, affect the properties of the resulting hybrids.
This research will involve graduate students, undergraduates, and high school students, and include gender, ethnic, and geographic minorities. The possible practical applications of these materials are in organic light-emitting devices, photovoltaics, and biomedical imaging.
This NSF-funded project aims at the design and preparation of novel transition metal clusters that are molecules containing multiple metal atoms in one unit with well-defined structures and the integration of these functional inorganic components with organic including polymeric moieties for the creation of inorganic-organic hybrid materials. The ultimate goals are to realize functional materials that are useful for applications for the development of advanced technologies that are of significance to the challenges we are facing in energy crisis, environmental protection, as well as in human health. The research takes advantage of 1) the unique chemistry supported by certain metal clusters and the functions or properties inherent to metal cluster compounds that are unavailable to single metal-containing molecules; 2) the desirable processibility of the organic components; and the prospects of generating new properties that are not available in either the metal cluster or the organic worlds. With this NSF support, we have developed systematically the new chemistry supported by the [Re6Se8] core-containing cluster system with the production of a series of new cluster compounds that are critical for the making of the hybrid materials. Utilizing cluster compounds as building blocks, we have successfully constructed a family of framework solids that possess large pores that are potentially useful for the recognition of guest molecules, storage of guests including hydrogen gas and carbon dioxide that are of significance to energy and environment, and efficient catalysis. We have also developed new methods to incorporate the clusters into polymeric matrices. Such cluster-polymer hybrids can be easily processed and of potential use as luminescent materials in organic light-emitting devices (LEDs). The cluster-supported chemistry and materials achieved are fundamentally new and contribute intellectually to the science of this unique class of chemical substances. The students undertaking this project have learned a wide range of knowledge and been trained in a number of disciplines. Our research involved graduate students, undergraduates, and high school students, and included gender, ethnic, and geographic minorities. In addition, for each year in the past three years, the PI has performed two chemistry magic shows for kindergarteners and elementary students, often involving results from this project, such as the demonstration of luminescence by the cluster-polymer hybrids. These efforts have been well received by not only the students but also the teachers. In terms of the broader impact based on the technical aspects of this proposed research, we are presently looking into the practical applications of such materials in organic light-emitting devices, photovoltaics, and biomedical imaging.
