Salen ligand
| |
| |
| |
| Names | |
|---|---|
| Other names
2,2'-Ethylenebis(nitrilomethylidene)diphenol, N,N'-Ethylenebis(salicylimine)
| |
| Identifiers | |
| ECHA InfoCard | 100.002.161 |
CompTox Dashboard (EPA)
|
|
| Properties | |
| C16H16N2O2 | |
| Molar mass | 268.31 |
| Appearance | yellow solid |
| Melting point | 125–129 °C (257–264 °F; 398–402 K) |
| organic solvents | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Salen is the abbreviation for a popular chelating ligand used in coordination chemistry and homogeneous catalysis. The name salen is a contraction for salicylaldehyde and ethylenediamine. The ligand is a bright yellow micaceous solid that is soluble in polar organic solvents.
Nomenclature
The diphenol H2salen is the conjugate acid of the ligand that logically is salen2-. But the terminology is used loosely. As an anionic tetradendate ligand, salen2- resembles tetradentate ligands including those that are macrocyclic, such as porphyrinate, corrin, bis(dimethylglyoximate), and some Schiff bases.
Preparation
SalenH2 is commercially available. It was first prepared by Pfeiffer.[1] It is often generated in situ followed by the addition of the metal salt, but the ligand is also easily prepared as a pure organic compound by the condensation of ethylenediamine and salicylaldehyde.[2]
References
- ^ P. Pfeiffer, E. Breith, E. Lübbe, T. Tsumaki (1933). ""Tricyclische orthokondensierte Nebenvalenzringe". Justus Liebig's Annalen der Chemie. 503: 84–130. doi:10.1002/jlac.19335030106.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Harvey Diehl, Clifford C. Hach (1950). "Bis(N,N' - Disalicylalethylenediamine) -μ - Aquodicobalt(II)". Inorg. Synth. Inorganic Syntheses. 3: 196–201. doi:10.1002/9780470132340.ch53. ISBN 978-0-470-13234-0.