Chemists make elusive carbon-bridged sandwich molecule once thought too strained to exist

Progress in chemistry is often gradual, with some of its most important advances taking years—sometimes decades—to unfold. A case in point is the discovery of a novel "ferrocenophane" from the class of compounds known as "sandwich molecules"—so named because of their particular structure. In a ferrocenophane, the "bread slices" are two carbon rings that enclose an iron atom as the sandwich "filling." A team of chemists at Saarland University has now succeeded in developing a highly unusual bent sandwich molecule that opens up new possibilities for designing iron-containing materials.