intercalation (rus. интеркаляция otherwise интеркалация) — (from Latin intercalatus "inserted, added") a reversible introduction of molecules, ions or atoms between molecules or groups (layers) of atoms of a different type.

Description

In solid state chemistry, intercalation usually refers to the process of reversible introduction of molecules or ions in the interlayer or other spaces within crystalline substances. The possible "host" substances include graphite, dichalcogenides of transition metals, layered double hydroxides, natural clays, etc., "guest" substances include atoms or ions of metals (alkali metal, Cu , Ag), charged complexes and neutral molecules forming discrete layers, separated by structural elements of the host. An important feature of intercalation is maintaining integrity of the "host" crystal structure; usually only a slight increase in the lattice parameters in one or several directions is observed. Intercalation may be accompanied by a significant change in the physical and chemical properties, electronic structure, electrical, magnetic and spectral characteristics of the host substance.

Intercalated compounds (intercalates) are used as catalysts, solid electrolytes, anode and cathode materials in primary and secondary power sources, solid lubricants, selective sorbents for separation and purification of substances. Intercalates formed by H2 introduction in the crystal lattices of intermetallic compounds, such as TiFe, LaNi5, Mg2Ni, contain hydrogen atoms weakly bound with the metal matrix and can be used as hydrogenation catalysts and hydrogen accumulators. The processes of intercalation-deintercalation of lithium ions form the functioning basis of the electrodes in lithium-ion batteries.

In biology and medicine intercalation usually refers to the incorporation of various ligands in the DNA molecule. This process is of great practical interest, in particular, because it allows the blocking of DNA replication and transcription in rapidly growing cancer cells, which is one of the main mechanisms of the effective anti-cancer drug Doxorubicin.

Author

  • Shlyakhtin Oleg A.

Sources

  1. Intercalation // Chemical encyclopedia (in Russian). V. 2. — Moscow: Sovetskaja ehnciklopedija, 1990. 243 p.
  2. Intercalation // Wikipedia, the free encyclopedia. — http://en.wikipedia.org/wiki/Intercalation_(chemistry)(reference date: 12.12.2011).

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