Organometallic Compounds for Nonlinear Optics—The Search for En‐light‐enment!

Abstract The importance of nonlinear optical phenomena has been known for some time, however, since the mid‐1980s, there has been an explosion of interest in the search for and development of non‐linear optical materials that possess commercial device applications. To date, the systems have been utilized in information processing, optical switching, optical frequency conversion, and telecommunications, and with the advancing development of optotechnology, burgeoning demands for suitable materials are becoming apparent. Of the many systems studied for example inorganic crystals and semiconductors, organic crystalline monomers, and long‐chain polymers with delocalized π electrons, no one species has proved to be all‐encompassing, with advantages for one application being negated by disadvantages for another. This is likely to remain the case for the foreseeable future with the criteria of the application governing the type of material used. However, chemists are gradually elucidating what actually governs second‐ and third‐order nonlinear activity and thereby, tailoring species to show greater effects. In recent years, organometallic compounds, through their unique characteristics such as diversity of metals, oxidation states, ligands, and geometries, have found success and brought a new dimension to the area. This review attempts, with critical appraisal, to bring the discussion of organometallic nonlinear optical systems up to date, as well as giving a brief but general introduction to the field of nonlinear optics. For corrigendum see DOI: 10.1002/anie.199508261