N,N'-Ethylenediaminedisuccinic acid
[CAS# 20846-91-7]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives
• Name: N,N'-Ethylenediaminedisuccinic acid
• Synonyms: (S,S)-Ethylenediaminedisuccinic acid; (S,S)-Ethylenediamine-N,N'-disuccinic acid; N,N'-1,2-Ethanediylbis-L-aspartic acid
• Molecular Formula: C₁₀H₁₆N₂O₈
• Molecular Weight: 292.24
• CAS Registry Number: 20846-91-7
• EC Number: 682-220-2
• SMILES: C(CN[C@@H](CC(=O)O)C(=O)O)N[C@@H](CC(=O)O)C(=O)O

Properties

• Density: 1.5±0.1 g/cm³ Calc.^*, 1.534 g/mL (Expl.)
• Melting point: 220-222 ºC (Expl.)
• Boiling point: 516.7±50.0 ºC 760 mmHg (Calc.)^*
• Flash point: 266.3±30.1 ºC (Calc.)^*
• Index of refraction: 1.562 (Calc.)^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H332-H335
• Precautionary Statements: P261-P280-P305+P351+P338

Discovory and Applicatios

N,N'-Ethylenediaminedisuccinic acid (EDDS) is a synthetic aminopolycarboxylic acid characterized by a central ethylenediamine core substituted with two succinic acid groups, one on each nitrogen atom. The molecule contains four carboxylic acid groups and two amine functions, giving it strong chelating properties. Its molecular structure is closely related to that of ethylenediaminetetraacetic acid (EDTA), a well-known chelating agent, but with two succinate units replacing the acetate units of EDTA. EDDS is most commonly encountered in its trisodium salt form (Na₃-EDDS), which is highly water-soluble.

EDDS was first developed and studied in the 1980s as part of a search for more environmentally friendly chelating agents. The traditional chelator EDTA, while effective in binding metal ions, exhibits poor biodegradability and accumulates in natural water systems, raising environmental concerns. In contrast, EDDS—particularly its (S,S)-stereoisomer—is readily biodegradable under aerobic conditions, making it suitable for use in green chemistry and sustainable applications.

The primary application of N,N'-ethylenediaminedisuccinic acid is in the chelation and removal of metal ions. Its four carboxylate groups and two nitrogen atoms allow it to form stable complexes with a wide variety of metal cations, including calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe³⁺), copper (Cu²⁺), lead (Pb²⁺), and cadmium (Cd²⁺). This makes EDDS useful in a range of industrial, environmental, and agricultural settings.

In household and industrial detergents, EDDS is used to sequester metal ions that would otherwise interfere with surfactant performance or cause scaling. Its use enhances cleaning efficiency by softening water and preventing the precipitation of insoluble metal salts. Because EDDS degrades quickly and completely under typical wastewater treatment conditions, it is considered an environmentally safer alternative to conventional chelators in cleaning products.

In agriculture, EDDS is used as a chelating agent to deliver micronutrients to plants, particularly in formulations where metal ions like iron or zinc need to be solubilized for uptake through roots. The biodegradability of EDDS minimizes the risk of long-term accumulation in soil and groundwater.

Environmental remediation is another significant application area. EDDS has been used in soil washing techniques to remove heavy metals from contaminated soils. It can effectively mobilize toxic metals like lead and cadmium from soil particles into aqueous solution, from which they can then be collected and treated. The use of EDDS in this context has the advantage of reducing metal toxicity without introducing persistent organic pollutants.

In laboratory and research settings, EDDS is employed as a chelator in analytical chemistry and biochemical assays where metal ions may interfere with reactions or measurements. It is also used in studies involving transition metal catalysis, where precise control of metal availability is required.

EDDS exists as three stereoisomers: (S,S)-EDDS, (R,R)-EDDS, and meso-EDDS. Of these, the (S,S)-form is most readily biodegradable and is thus favored for use in environmental and commercial applications. The isomers differ in the spatial arrangement of the succinate groups, which influences the stability constants of their metal complexes and their degradation behavior.

Synthesis of EDDS typically involves the condensation of ethylenediamine with maleic or fumaric acid derivatives, followed by hydrogenation and hydrolysis to yield the final aminopolycarboxylic acid. Depending on the synthetic route, mixtures of stereoisomers may be obtained, but resolution methods are available to isolate the (S,S)-isomer when required.

In summary, N,N'-ethylenediaminedisuccinic acid is a biodegradable aminopolycarboxylic acid chelator used in detergents, agriculture, environmental remediation, and research. It serves as a sustainable alternative to non-degradable chelating agents, offering effective metal binding with a significantly lower environmental impact.

References

2020. Aminocarboxylic acids related to aspergillomarasmine A (AMA) and ethylenediamine-N,N'-disuccinic acid (EDDS) are strong zinc-binders and inhibitors of the metallo-beta-lactamase NDM-1. Chemical communications (Cambridge, England), 56(20).
DOI: 10.1039/d0cc00356e

2018. Ethylenediamine-N,N'-Disuccinic Acid (EDDS)�Enhanced Flushing Optimization for Contaminated Agricultural Soil Remediation and Assessment of Prospective Cu and Zn Transport. International Journal of Environmental Research and Public Health, 15(3).
DOI: 10.3390/ijerph15030543

2017. Bacterial zincophore [S,S]-ethylenediamine-N,N'-disuccinic acid is an effective inhibitor of MBLs. The Journal of antimicrobial chemotherapy, 73(2).
DOI: 10.1093/jac/dkx403