Eight-coordinate fluoride in a silicate double-four-ring.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28096342.
- Also identified by DOI 10.1073/pnas.1615742114 and PMC identifier 5293034.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Fluoride, nature's smallest anion, is capable of covalently coordinating to eight silicon atoms. The setting is a simple and common motif in zeolite chemistry: the box-shaped silicate double-four-ring (D4R). Fluoride seeks its center. It is the strain of box deformation that keeps fluoride in the middle of the box, and freezes what would be a transition state in its absence. Hypervalent bonding ensues. Fluoride's compactness works to its advantage in stabilizing the cage; chloride, bromide, and iodide do not bring about stabilization due to greater steric repulsion with the box frame. The combination of strain and hypervalent bonding, and the way they work in concert to yield this unusual case of multiple hypervalence, has potential for extension to a broader range of solid-state compounds.