ABSTRACT
The host material can be a crystalline solid, a polymer, or a glass formed by freezing a liquid or solidifying a gas. The term
matrix isolation
is, however, most commonly used in a more restricted sense to refer to the technique of trapping guest species in solidified inert gases, such as neon, argon, krypton, or nitrogen. In this form, the technique requires very low temperatures — typically 4 to 20 K. Occasionally, when it is desired to observe specific host-guest reactions, reactive gases such as methane, carbon monoxide, or oxygen are utilized as matrix hosts.
