In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division, John Sheridan and Frieder Jakle of Rutgers University at Newark will explore how scorpionate-type ligand modified polymers can be prepared and used to make assemblies of macromolecules with complex architectures and functions. The approach is to synthesize monomers that contain bidentate and tridentate ligands based upon neutral organosilicon and anionic organoborate scorpionate structures. The direct polymerization of these monomers will be studied, and polymer postmodification approaches will be examined as well. The resulting macromolecules will be complexed to metal ions and metal complex fragments to create a range of new structures with potentially interesting electrochemical, thermal, and optical properties. The broader impacts involve dissemination of research results via publications and seminars at conferences, training graduate students and postdoctoral researchers, participation in Project SEED, and continued development of a high school outreach program on polymer and materials chemistry.
This work will enhance our fundamental understanding about how to prepare polymers that contain metals. The results of these studies could have many important long term impacts on solar energy, biomedical, and sensing technologies.
The research supported under this grant involved the synthesis of polymers with well-defined architectures that can bind metals. Such materials allow us to take advantage of the unique electronic, magnetic, optical characteristics and catalytic behavior of transition metal complexes, as well as the processability and self-assembly properties of polymers, within a single substance. The polymers studied contain polypyridyl binding sites for the attachment of metal complexes that are side chain groups of traditional polystyrene or polynorbornene backbones. They were prepared by controlled polymerization of new neutral organosilicon and (isoelectronic) anionic organoborate containing monomers that were expected to serve a dual role. In addition to acting as convenient structural building blocks, these groups or linkers can themselves provide desirable additional functionality. Specifically, we have prepared monomers containing tris(pyridyl)- borate, silane and methane moieties with styrene, norbornene and acrylate groups. Controlled polymerization via atom transfer radical polymerization (ATRP), nitroxide-mediated polymerization (NMP), reversible addition-fragmentation chain transfer (RAFT), and ring-opening metathesis polymerization (ROMP) was explored; NMP and ROMP produced a series of well-defined polymers and block copolymers. Solvent-specific self-assembly of these polymers was demonstrated and their binding to metals such as magnesium, iron, ruthenium and copper was shown to provide stimuli-responsive materials. The broader impact activities involved: (i) Training a diverse group of graduate, undergraduate and high school students. Two postdoctoral researchers, four graduate students and two undergraduate students have been involved in our research program and trained in a multidisciplinary environment that involves aspects of organic synthesis, inorganic complex chemistry, and polymer/materials science. (ii) Broadening participation of underrepresented groups through high school outreach programs. The PIs have co-organized outreach programs with McNair Academic high school in Jersey City, NJ. A total of close to 130 students attended the sessions over the four-year grant period. The PI’s have hosted 3 ACS project SEED high school students during the summers to participate in the project. (iii) Dissemination of new knowledge through organization of symposia in the area of organic-inorganic hybrid materials. One of the PI’s has co-organized a symposium on "Nanostructure and function of organic-inorganic hybrid polymers" at Pacifichem 2010. A symposium entitled "Main Group Chemistry Meets Polymer and Materials Sciences" was organized at the Fall 2012 ACS National Meeting in Philadelphia.
