Properties and Applications of N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine

N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine is an amino alcohol compound that exists as a transparent, colorless liquid under ambient temperature and pressure. It exhibits high polarity and good chemical stability, shows moderate solubility in water, and is miscible with most organic solvents. As a cross-linking agent and antistatic agent, N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine is widely used in synthetic rubber and polyurethane products, where its incorporation imparts excellent mechanical strength and antistatic properties to the final materials. Additionally, N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine serves as a stabilizer in engineering plastics, enhancing their light resistance and cold tolerance.

Figure1 : Picture of N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine

Complexation of copper ions

Through constant current polarographic analysis at 20°C and an ionic strength of 3 mol·L⁻¹, the formation of Cu²⁺ ion complexes with N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine (Quadrol-Q) was investigated. Within the pH range of 6 to 8, the study indicated the possible formation of two complex species: CuQ²⁺ and CuQ₂²⁺, whose logarithmic stability constants were determined to be 10.6 ± 0.3 and 14.6 ± 0.4, respectively. A sharp increase in Cu(II) complexation was observed as pH rose from 8 to 10. Furthermore, at pH values above 10, the experimental data align with the presence of hydroxy complexes CuQ(OH)₂ and CuQ₂(OH)₂, with logarithmic stability constants of 26.9 ± 0.5 and 29.1 ± 0.3, respectively, further elucidating the coordination behavior of N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine under alkaline conditions. [1]

Complexation of cobalt ions

This study describes the synthesis, crystal structure, and biological properties of the complex [Co(edtp)Cl]NO₃·H₂O, where edtp represents N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine. The Co²⁺ ion is coordinated in a pentadentate manner through the N,N′,O,O′,O′′ donor set of the N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine ligand along with a chloride ion, forming a distorted CoClN₂O₃ octahedral geometry. Biologically, the complex demonstrates moderate antithrombolytic activity (38% as screened by hemolytic assay) against bovine blood clots while exhibiting negligible cytotoxicity (5%) toward bovine erythrocytes. In contrast, it displays strong bacterial biofilm inhibition (90%) against both Gram‑positive and Gram‑negative bacterial strains. The neutral ligand edtp, which can be viewed as a ‘double diethanolamine’ derivative, is capable of acting as a multidentate and/or bridging ligand; an extensive series of its complexes with Na⁺, Ca²⁺, Sr²⁺, and Ba²⁺ has been previously reported, whereas transition‑metal complexes with edtp remain less explored, although recent studies have described copper and silver complexes along with their antimicrobial profiles. Previously, we reported Fe–Ln complexes employing the structurally similar ligand N,N,N′,N′-tetrakis(2‑hydroxyethyl)ethylenediamine (H₄edte). In the present work, we report a new cobalt complex with edtp and evaluate its biofilm inhibitory, hemolytic, and antithrombolytic activities. Thecomplex[Co(edtp)Cl]NO3H2Owassynthesizedandits structure established by single-crystal diffraction. The N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine ligand is penta-coordinated to the cobalt ion via its nitrogen and oxygen atoms, resulting in a distorted CoO3N2Cl octa hedral geometry. The complex exhibits promising bacterial biofilm inhibition and shows moderate antithrombolytic activity against clots developed by human blood. It has neg ligible cytotoxicity against human erythrocytes. [2]

Chemical Applications

N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine can be used as a crosslinking agent and antistatic agent in synthetic rubber and polyurethane products. In cosmetics and skincare products, N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine primarily functions as a chelating agent. It has a risk factor of 1, indicating a high safety profile, and can be used with confidence. This ingredient is generally considered safe for pregnant women and is non-comedogenic. Research has reported that N,N,N',N'-tetrakis-(2-hydroxypropyl)ethylenediamine can be used in the preparation of aqueous electroless copper plating solutions, which include: a copper ion source, a reducing agent or reducing agent source, and a complexing agent composition. This composition contains i) N,N,N',N'-Tetrakis(2-hydroxypropyl)ethylenediamine or its salts, and ii) N'-(2-hydroxyethyl)ethylenediamine-N,N,N'-triacetic acid or its salts. The study also describes methods for electroless copper plating using the solution and its application for coating substrates.

References

[1] Frank Brüning, Birgit Becker, Elisa Langhammer, et al. Electroless copper plating solution: CN201480011888.7[P].

[2] Muhammad Nadeem Akhtar, Synthesis, crystal structure and biological activity of a cobalt(II) complex of N,N,N0,N0-tetrakis(2-hydroxypropyl) ethylenediamine, Transition Met Chem 2016, 41:325–330.