The figure depicts the processes of removing an electron from the negatively-charged radical anion of 1,7-C60(C8F17)2, in the gas-phase by low-temperature photoelectron spectroscopy and in solution by cyclic voltammetry. Image by Alexey A. Popov

Organofluorines form a large and extremely useful family of chemical compounds. They are used in vast array of applications, in the industry, in medicine and, not the least, in organic photovoltaic (OPV) devices, primarily efficient solar cells. Since the applications of any given compound depend on its electronic properties and since the large (and growing) number of organofluorines makes it difficult to measure said properties for all possible compounds, chemists devised simple linear models which can be used to predict the properties of organofluorines from measured properties of similar compounds.

But, it turns out that reality is not that simple. In a recent study of organofluorines researchers found that the theoretical correlations of electronic properties don’t always work and that even a simple carbon-fluorine group can change its properties depending on its location on a fullerene cage.

This study, which has shaken up the field of organofluorine chemistry, was the cover article in the May 2012 issue of Chemical Science. Large part of the study included precise x-ray crystallographic measurements and was performed at the ChemMatCARS facility, at the APS.

“The collaboration with Yu-Sheng Chen at ChemMatCARS was important for the project,” said team member and co-author Olga V. Boltalina. “The facilities he developed can handle the smallest crystals of fullerenes and his expertise in x-ray characterization and solid-state packing of molecules were invaluable.”

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