Salen ligand

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Salen ligand
Salen.jpg
Salen structure.svg
Salen-3D-balls.png
Identifiers
CAS number 94-93-9 YesY
Properties
Molecular formula C16H16N2O2
Molar mass 268.31
Appearance yellow solid
Melting point 125 to 129 °C (257 to 264 °F; 398 to 402 K)
Solubility in water organic solvents
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

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[edit]

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[edit]

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]

Preparation of salen.png

References[edit]

  1. ^ 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. 
  2. ^ 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. 

See also[edit]