Co-principal investigator Benjamin P. Hay, a chemist at the Pacific Northwest National Laboratory in Richland, Wash., where Berryman studied last fall as part of UO's National Science Foundation-funded internship program, said the study has important ramifications in anionophore design, crystal engineering and other aspects of supramolecular chemistry. In fact, he said, the findings indicate that prior designs may be flawed, incomplete or even misleading. "We discovered an unexpected bonding motif that involves the transfer of charge from the anion to the arene -- in other words, a covalent bonding motif," Hay said. "This is the first theoretical characterization of what we have termed an off-center, weak charge-transfer interaction."
Anions, of which notable examples include DNA, nitrate, pertechnetate, cyanide and chromate, play indispensable roles in biological and chemical processes, but they also can contribute significantly to environmental pollution that threatens aquatic life cycles and human health.
Johnson, in collaboration with UO chemist Michael M. Haley, now is seeking to design receptors that aim to the off-center location, with a goal of developing sensors for anion detection. Because Berryman's research produced sometimes intense color changes at binding sites, such an approach could lead to developing materials that sense the presence of these toxins and remediate them.
While 0.2 nanometers seems an insignificant distance, it could mean there's a 100 percent chance that binding cannot occur, Johnson said. "We're finding that from a design standpoint, that 0.2 nanometers is a big di
Contact: Jim Barlow
University of Oregon