New Molecular Systems Based on Indenofluorenes and Expanded Quinoidal Analogues: Experimental, Theoretical, and Materials Studies

University Of Oregon Eugene, Eugene OR

Investigators

Abstract

The Chemical Synthesis Program of the NSF Chemistry Division supports the research of Professor Michael Haley in the Department of Chemistry & Biochemistry at the University of Oregon. Prof. Haley and his students are preparing molecules based on or inspired by the indenofluorene skeleton to answer fundamental scientific questions as well as to explore their materials properties. A key goal is to develop simple synthetic methods for the assembly of these strongly electron-accepting molecules. Once in hand, the Haley group examines the optical and electronic properties of all new molecular scaffolds with an emphasis towards utilization of these materials in optoelectronic devices such as organic field effect transistors (OFETs) and organic photovoltaics (OPVs). The broader impacts of this program include industrial internships for graduate students at local and regional companies, the exchange of graduate students with those of foreign collaborators, the hosting of extended stays of visiting scientists including professors from primarily undergraduate institutions (PUIs), and continued substantial involvement of undergraduates in chemical research via programs which promote participation of underrepresented groups. Research on non-benzenoid molecules has experienced a renaissance over the last decade as chemists have recognized their potential as organic semiconductors characterized by low Highest Occupied Molecular Orbitals (HOMO) and Lowest Unoccupied Molecular Orbitals (LUMO) energy levels and small energy gaps. This projects sets out to: (1) explore the fundamental properties and reactivity of the fully conjugated indenofluorene (IF) core leading to asymmetrically derivatized structures, (2) prepare a library of derivatized IFs and IF-diones for detailed structure-properties relationship studies, (3) extend our synthetic routes for the preparation and study of unknown, fully conjugated topologies such as indeno[1,2-a]fluorenes and indacenodiacenes, and (4) prepare expanded quinoidal IF analogues based diindeno-fused acenes and explore their open shell/biradical character. The molecules developed in these studies present opportunities for practical applications, particularly in the area of nanotechnology and low-cost electronics. Moreover, this project serves as an excellent training ground for graduate and undergraduate researchers in fundamental and applied chemical synthesis. The studies provides the researchers with broad experience in organic synthesis, computational chemistry, x-ray crystallography, and the interplay between electronic structure and molecular architecture.