Salen ligand
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| Names | |
|---|---|
| Other names 2,2′-Ethylenebis(nitrilomethylidene)diphenol, N,N′-Ethylenebis(salicylimine) | |
| Identifiers | |
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3D model (JSmol) | |
| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.002.161 |
| EC Number |
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PubChem CID | |
| UNII | |
CompTox Dashboard (EPA) | |
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| Properties | |
| C16H16N2O2 | |
| Molar mass | 268.32 |
| Melting point | 126 °C (259 °F; 399 K) |
| Hazards | |
| GHS labelling: | |
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| Warning | |
| H315, H319, H335 | |
| P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Salen refers to a tetradentate C2-symmetric ligand synthesized from salicylaldehyde (sal) and ethylenediamine (en). It may also refer to a class of compounds, which are structurally related to the classical salen ligand, primarily bis-Schiff bases. Salen ligands are notable for coordinating a wide range of different metals, which they can often stabilise in various oxidation states.[1] For this reason salen-type compounds are used as metal deactivators. Metal salen complexes also find use as catalysts.[2]
Synthesis and complexation
[edit]H2salen may be synthesized by the condensation of ethylenediamine and salicylaldehyde.[3]
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Complexes of salen with metal cations can often be made in situ, i.e., without isolating the H2salen.[4][5]
- H2salen + M2+ → M(salen) + 2 H+
See also
[edit]- Bisthiosemicarbazones, a structurally related class of C2-symmetric imine based ligands
References
[edit]- ^ Cozzi, Pier Giorgio (2004). "Metal–Salen Schiff base complexes in catalysis: practical aspects". Chem. Soc. Rev. 33 (7): 410–421. doi:10.1039/B307853C. PMID 15354222.
- ^ Shaw, Subrata; White, James D. (11 June 2019). "Asymmetric Catalysis Using Chiral Salen–Metal Complexes: Recent Advances". Chemical Reviews. 119 (16): 9381–9426. doi:10.1021/acs.chemrev.9b00074. PMID 31184109. S2CID 184486101.
- ^ Tsumaki, T. (1938). "Nebenvalenzringverbindungen. IV. Über einige innerkomplexe Kobaltsalze der Oxyaldimine". Bulletin of the Chemical Society of Japan (in German). 13 (2): 252–260. doi:10.1246/bcsj.13.252.
- ^ Diehl, Harvey; Hach, Clifford C. (1950). "Bis( N,N '-Disalicylalethylenediamine)-μ - Aquodicobalt(II)". Inorganic Syntheses. Vol. 3. pp. 196–201. doi:10.1002/9780470132340.ch53. ISBN 978-0-470-13234-0.
{{cite book}}:|journal=ignored (help) - ^ Pier Giorgio Cozzi (2004). "Metal-Salen Schiff base complexes in catalysis: Practical aspects". Chem. Soc. Rev. 33 (7): 410–421. doi:10.1039/B307853C. PMID 15354222.