Cherry picking molecules based on their Pi electrons
Specialized windshield glass, everyday plastic water bottles, and countless other products are based on ethylene, a simple two-carbon molecule, which requires an energy-intense separation process to pluck the desired chemical away from nearly identical ethane. To eliminate the extreme cooling required in the separation, an international team including researchers at Pacific Northwest National Laboratory designed a material with a porous framework that greatly prefers ethylene. What makes this material particularly potent for applications is that the highly selective sorbent is stable in air and water. In addition, the framework offers a high surface area that speeds the sorting. The material contains silver that binds with the electrons around ethylene's double-bonded carbon atoms. These electrons are known as π electrons or the π cloud.