Isolability

Isolability refers to the property of a chemical species or other entity to be separated from its surroundings and prepared in a pure, storable form under specified conditions. In chemistry, an isolable substance can be prepared, isolated in a defined phase (often as a solid or pure solution), and characterized by standard analytical techniques. The concept is closely tied to the practical ability to handle, store and study the species outside its native reaction context.

Isolability contrasts with transient or highly reactive species that exist only for a short time under a given set of conditions. Whether a species is isolable depends on its stability under isolation conditions, as well as kinetic factors that slow its decomposition or transformation. Thermodynamic stability concerns the energy difference between products and reactants, but a species can be kinetically stabilized and therefore isolable even if not thermodynamically favored under ambient conditions.

Examples of isolable chemical species include many organic compounds, inorganic salts, and well-characterized organometallic complexes. By contrast, reactive intermediates such as certain carbenes or nitrenes are typically not isolable in free form, unless stabilized by strong steric protection, coordination to a metal, or low temperatures. N-heterocyclic carbenes, for instance, are widely studied as isolable, stable carbenes protected by ring systems.

Practically, isolability is achieved through synthesis and purification under controlled conditions (inert atmosphere, low temperature, dry solvents), followed by storage and handling that prevent decomposition or reaction with air, moisture, or light. The assessment of isolability involves isolation, purification, and characterisation using spectra, crystallography, and other analytical methods.