Kaasasoluvat

Kaasasoluvat, or gas solvates, are crystalline inclusion compounds in which gas molecules are physically trapped within a solid host lattice formed by a solvent or framework. In these adducts the gas is not simply dissolved; it occupies voids within the host material, producing a defined stoichiometry that can vary with the specific system.

Formation usually involves exposing a crystalline host, such as an organic solvent crystal, cyclodextrin, or a porous solid like a metal–organic framework or a molecular crystal, to a gas under controlled temperature and pressure. The occupancy of gas molecules depends on factors including pressure, temperature, and the size and shape of the host’s cavities. Characterization methods commonly used include X-ray crystallography, infrared or Raman spectroscopy, and solid-state NMR, which help determine where the gas sits and how the lattice behaves.

Properties of gas solvates are governed by the stability of the host–gas interaction and the conditions needed to desolvate. Desolvation typically releases the gas upon heating or pressure change, enabling reversible gas uptake and release cycles. Some systems may exhibit hysteresis or solid-state phase transitions during uptake and release.

Applications and significance of kaasasoluvat include potential uses in gas storage and controlled release, gas separation and purification, and studies of host–gas interactions in crystal engineering. They are related to, but distinct from, gas hydrates (clathrates) in which water forms the host lattice, whereas kaasasoluvat rely on organic or inorganic solvent-based hosts.