| SPANphos | |
|---|---|
|
4,4,4',4',6,6'-Hexamethyl-2,2'-spirobichroman-8,8'-diylbis(diphenylphosphane) |
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| Properties | |
| Molecular formula | C47H46O2P2 |
| Molar mass | 704.814 g/mol |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
SPANphos is an organophosphorus compound used as a ligand in organometallic and coordination chemistry. This compound is a rare example of a trans-spanning ligand and rigidly links mutually trans coordination sites. By virtue of its chiral backbone that forms a chiral cavity over the face of a square planar complexes, e.g. in MCl2(SPANphos) (M = Pd, Pt).
This C2-symmetric trans-diphosphine is synthesized from inexpensive reagents. In the first step 4,4,4',4',6,6'-hexamethyl-2,2'-spirobichroman is prepared via an acid-catalyzed reaction between p-cresol and acetone. The spirane is brominated with N-bromosuccinimide, and the resulting dibromide is metalated with n-BuLi. Treatment of the resulting dilithio derivative with chlorodiphenylphosphine completes the synthesis.[1]