Building it better
Calling familiar assumptions into question results in better materials design
Carbon and fluorine are at the heart of a family of chemical compounds that can be used for nonstick coatings, blood substitutes, and seemingly everything in between. Differences in the structures of these compounds, called organofluorines, dictate their suitability for different applications. But how can these structures be optimized to improve their performance? How can they be designed to perform new jobs? In their search for answers, researchers called into question some commonly held chemistry assumptions. And by doing so, they dramatically improved chemists’ ability to design and synthesize new organofluorine-based materials. Previously, it was thought that simple linear equations related three electronic and electrochemical properties having to do with the energy required for electrons and molecules to assemble or break apart—properties very important for molecular electronics. In an unprecedented find featured on the May cover of Chemical Science, the research team discovered that the three properties are not always correlated. This lack of correlation is unexpected and suggests possible explanations for observed differences in materials and device behaviors. Their findings are based on a study of seven different organoflourine groups attached to buckyballs—a special arrangement of carbon atoms shaped like a soccer ball and whose unique chemistry holds promise for practical uses. The team investigated the electronic and electrochemical properties of these organofluorine-buckyballs using a combination of computational, electrochemical, and spectroscopic methods, including photoelectron spectroscopy at EMSL. The new knowledge afforded by their study will help chemists better choose the right organofluorine groups to design new materials with optimized morphological, electronic, optical, and/or magnetic properties.
Reference: Kuvychko IV, JB Whitaker, BW Larson, TC Folsom, NB Shustova, SM Avdoshenko, Y Chen, H Wen, X Wang, L Dunsch, AA Popov, OV Boltalina, SH Strauss. 2012. “Substituent effects in a series of 1,7-C60(RF)2 compounds (RF = CF3, C2F5, n-C3F7, i-C3F7, n-C4F9, s-C4F9, n-C8F17): electron affinities, reduction potentials and E(LUMO) values are not always correlated.” Chemical Science 3(5):1399-1407. DOI: 10.1039/c2sc01133f
Participants: Colorado State University, Dresden University of Technology, Argonne National Laboratory, Pacific Northwest National Laboratory, Washington State University, Liebniz Institute for Solid State and Materials Research
Acknowledgments: This work was supported by the National Science Foundation and the Colorado State University Research Foundation. Photoelectron spectroscopy experiments were supported by the U.S. Department of Energy, Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences and performed at EMSL, a national scientific user facility located at Pacific Northwest National Laboratory. The Advanced Photon Source, a national scientific user facility located at Argonne National Laboratory, also contributed to this research.
Released: May 22, 2012