With the support of the Organic Dynamics Program in the Chemistry Division, Professor Frieder Jaekle of the Chemistry Department at the Rutgers University- Newark will develop synthetic routes that will provide highly selective and controlled access to new classes of conjugated organoboron oligomers, macrocycles, and polymers ? all from the same set of precursor molecules. The modular approach that is being developed is expected to allow for facile optimization of the desired materials properties, photophysical characteristics, electronic behavior, and sensing ability. To evaluate and fine-tune the degree of extended conjugation through p-pi overlap will be of critical importance. It is anticipated that this project will generate new fundamental knowledge in the field of main group chemistry and in the areas of conjugated organic and hybrid materials.
Research by Professor Jaekle at Rutgers University- Newark will in the longer term contribute to the development of novel and more efficient conjugated materials that can be used in applications such as plastic electronics and sensors. The project will effectively contribute to the training of a diverse body of undergraduate and graduate students in a highly interdisciplinary area that involves aspects of physical organic chemistry, organometallic chemistry, polymer chemistry, and materials science. The experience gained through this research is of direct relevance to the chemical industry in the US. Another important aspect is to build bridges between undergraduate education and research. As part of this award, a new experiment on luminescent sensor materials will be added to a senior laboratory course. Professor Jaekle will also continue to involve ACS Project SEED high school students in the research and continue the very successful outreach programs with local high schools that were established as part of the prior award.
. These novel materials are, for example, of interest with respect to potential applications as optoelectronic device materials in OLEDs, as luminescent chemosensors for the detection of toxic chemicals, and more generally as building blocks for advanced polymeric materials. 1) A question of fundamental importance with regard to the properties of conjugated organoboron polymers is how effective the extended conjugation through the conjugated pi-system and the empty p orbital on boron is. We addressed this question using an experimental approach, in which we prepared well-defined oligomers of exact chain length and compared their photophysical properties and electronic structure. With extension of the chain length we found a gradual bathochromic shift in the absorption spectra and at ca. 5 repeating units the absorption maximum approached that of a corresponding high molecular weight polymer. 2) Polymeric materials are expected to serve as important components in the next generation of display technology, ranging from small displays for cellular phones to TV screens and large area displays. We developed a highly versatile organoboron polymer backbone in our laboratory that allows us to prepare polymers with advantageous properties for potential use in electron conduction and emitting layers in organic light emitting devices (OLEDs) through simple polymer modification reactions. 3) We demonstrated that these organoboron oligomers and polymers can also serve as polymeric sensory materials, which rely on the selective interaction of the substrate with the luminescent oligomer or polymer. The response in the absorption and emission characteristics is highly specific and can readily be verified via spectroscopic screening. This work allows for efficient and selective detection of fluoride and cyanide anions. Broader impact activities: 1) Involvement of Economically Disadvantaged High School Students and Undergraduate Students in our Research Program: We hosted two ACS Project SEED summer student and two undergraduate students have been directly involved in the research. 2) Broad Dissemination of Fundamental Knowledge: The PI put together a comprehensive review on "Advances in the Synthesis of Organoborane Polymers for Optical, Electronic, and Sensory Applications", published in the ACS journal Chemical Reviews in 2010. Under the auspices of the New Jersey Polymer Topical Group, the PI organized a symposium on 'Polymers as Sensory and Energy-Related Materials' (May 14, 2009). The PI also co-organized two symposia at the 2010 Pacifichem Meeting ('Nano Structure and Function of Organic-Inorganic Hybrid Polymers' (#152) and 'Organoboron, Organosilicon and Organophosphorus as Optoelectronic and Energy-related Materials' (#35)). 3) Highschool Outreach Program: The PI organized an outreach program with McNair high school in Jersey City, NJ. About 50 high school students visited Rutgers on June 11, 2010. The one-day program consisted of demonstrations of research at Rutgers Newark, short introductions to the undergraduate program and honors college, and concluded with hands-on experiments relating to polymer and materials research.
