Anioneilles

Anioneilles are a hypothetical class of negatively charged molecular species proposed in speculative chemistry to describe highly delocalized anions that feature a compact core of interconnected atoms. The term blends the concept of anions with a diminutive suffix to indicate small, discrete units within a larger framework.

In the proposed models, anioneilles are envisioned to contain a central framework, often based on chalcogen or pnictogen elements, surrounded by electron-rich ligands. Charge is distributed over several centers through resonance and sometimes hypervalent bonding, which can confer greater stability against simple protonation or nucleophilic attack than typical monoanions. They may adopt multiple conformations, ranging from cyclic to open-chain topologies.

Theoretical work suggests they could be stabilized by coordination to metal cations or by encapsulation in host matrices. Possible formation routes include reduction of suitable neutral precursors or metathesis reactions carried out under stringent conditions. To date, there are no confirmed isolations of anioneilles in experimental practice, and proposed synthesis routes remain speculative.

Characterized by their delocalized charge, anioneilles are predicted to exhibit distinctive spectroscopic signatures. They may show strong absorptions in the ultraviolet-visible region due to distributed electronic transitions, with infrared features associated with the core framework and its ligands. Electron paramagnetic resonance could appear if unpaired electrons are present in certain forms, while NMR signals might be broadened or attenuated by rapid exchange within the framework.

As of now, anioneilles occupy a theoretical niche rather than an established class of compounds. If realized experimentally, they could find interest as redox-active components, charge-transport media, or catalytic systems where highly delocalized negative charge is advantageous. Further experimental validation is required to confirm their existence and properties.