Conjugated Polymer Networks Christoph Weder, Case Western Reserve University DMR-0215342

1. Conjugated Polymer NetworksChristoph Weder, Case Western Reserve UniversityDMR-0215342 This research program addresses the investigation of conjugated polymer networks, a little-explored class of materials with interesting optic and electronic properties. For example, some of the semi-conducting materials developed under this grant exhibit superior charge transport characteristics. The network structure, however, renders these polymers intractable and therefore their synthesis and processing is intricate. Recent work by graduate student Akshay Kokil and undergraduate student Peter Yao demonstrated that conjugated polymers such as poly(p-phenylene ethynylene)s (PPEs) with 2,2’-bipyridine (Bipy) moieties in their backbone represent versatile precursors for conjuga-ted metallo-supramolecular networks. These materials are readily accessible via ligand-exchange reactions between the Bipy-containing polymers and transition metals such as Zn2+, Cd2+, Cu+, Co2+ and Ni2+. Metallo-supramolecular networks are formed by ligand-exchange between 2,2’-bipypridine-containing poly(p-phenylene ethynylene)s and transition metal complexes. Absorption spectra acquired upon addition of [CuI(CH3CN)4]PF6 to asolution of Bipy-containing PPE. The inset shows the absorption at 452 nm as a function of [Cu+]:[Bipy] ratio. Kokil, A.; Yao, P.; Weder, C. Macromolecules2005, 38, 3800.

2. Conjugated Polymer NetworksChristoph Weder, Case Western Reserve UniversityDMR-0215342 Education: This grant provides/provided partial support for 3 graduate students (Mr. A. Kokil, Ph.D.; Ms. C. Rademaker, M.S.; Mr. J. Mendez, Ph.D.) and 5 undergra-duate students (Ms. S. Given, Mr. P. Yao, Mr. D. Wilger, Mr. E. Yamaguchi). Outreach: The grant supports two outreach programs which the PI developed in collaboration with Cleveland’s Museum of Natural History and Case colleague Stuart Rowan. Each year the Case team hosts the “Future Scientists Program” (a class of prospective scientists age 13-17) for a hands-on day of polymer activities. The team is also part of the Museum’s “Winter Discovery Day”, an annual 1-day event in honor of Dr. Martin Luther King Jr. In the last two years, over 1400 guests of all backgrounds and ages visited the polymer exhibits at the Museum, put together by the Case PIs and their students. The 20-min tours featured mini-lectures, displays, demos and hands-on activities that showcase the importance of polymers. Graduate student Brent Crenshaw explains the similarity of building blocks and Gummi Bears.

3. Conjugated Polymer NetworksChristoph Weder, Case Western Reserve UniversityDMR-0215342 Extra pictures from the winter discovery day 2005. Undergraduate student Kara Smith explains the similarity of building blocks and Gummi Bears. Graduate student Ben Beck and postdoc Dan Knapton explain the concept of macromolecules.