EDDS

• EDDS
• Ethylenediamine

• 20846-91-7
• 178949-82-1 ( trisodium salt )

Fixed

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Ethylenediaminedisuccinic ( ethylenediamine abbreviated EDDS) as a polydentate ligand chelate formers. It has a similar chemical structure and properties similar to EDTA. It has two stereogenic centers, so that it occurs in three different stereoisomers: the S, S, R, R and R, S- ( meso ) -EDDS. Of these, the S, S- EDDS easily completely biodegradable and the R, S- EDDS partially biodegradable; problematic is the R, R - stereoisomer, which is persistent in the environment. However, EDDS appears to be at least partially biodegradable substitute for the comparatively extremely durable EDTA. The S, S- stereoisomer is a derivative of the natural amino acid L- aspartic acid - this is leading to the good biodegradability.

Occurrence

In various actinomycetes S, S- EDDS occurs naturally.

Production and representation

A simple, large industrially viable easy access to EDDS, the addition of ethylene maleic anhydride dar. However, one obtains in this way a mixture of stereoisomers, which equal parts of the (S, S) - and (R, R) -isomer and the ( R, S)- isomer ( meso- form = ) consists.

Focused, but also more expensive synthesis of (S, S)- EDDS is the reaction of L- aspartic acid with 1,2- dibromoethane.

Use

EDDS serves as a substitute for EDTA. The complex formation constants for the chelate complexes with metal ions are usually only slightly smaller than that of EDTA, such that it could replace this largely. The areas of application are similar to those of edtas, eg

• Addition to cleaning agents ( water softening by binding of Ca2 / Mg2 ),
• Complexation of heavy metal ions,
• Soil washing heavy metal contaminated Erdraums.