Matrix isolation

Initially the term matrix-isolation was used to describe the placing of a chemical species in any unreactive material, often polymers or resins, but more recently has referred specifically to gases in low-temperature solids.

Mono-atomic gases have relatively simple face-centered cubic (fcc) crystal structure, which can make interpretations of the site occupancy and crystal-field splitting of the guest easier.

Using the matrix isolation technique, short-lived, highly-reactive species such as radical ions and reaction intermediates may be observed and identified by spectroscopic means.

For example, the solid noble gas krypton can be used to form an inert matrix within which a reactive F3− ion can sit in chemical isolation.

[4] Matrix isolation has its origins in the first half of the 20th century with the experiments by photo-chemists and physicists freezing samples in liquefied gases.

The earliest isolation experiments involved the freezing of species in transparent, low temperature organic glasses, such as EPA (ether/isopentane/ethanol 5:5:2).

In the 1970s, Koerner von Gustorf's lab used the technique to produce free metal atoms which were then deposited with organic substrates for use in organometallic chemistry.

With the work of chemists like these, laser-vaporization in matrix isolation spectroscopy rose in popularity due to its ability to generate transients involving metals, alloys and semi-conductor molecules and clusters.