Complexation of Cu(II) by Original Tartaric Acid−Based Ligands in Nonionic Micellar Media: Thermodynamic Study and Applications

Abstract

The complexation of Cu(II) with original alkylamidotartaric acids (C(x)T) is investigated in homogeneous aqueous medium and in the presence of nonionic micelles of Brij 58 (C16EO20), thanks to various analytical techniques such as NMR self-diffusion experiments, CD and UV-vis spectroscopy, ESI mass spectrometry, pHmetry and micellar-enhanced ultrafiltration (MEUF). First, a complete speciation study proves the formation of dimeric complexes in water and provides their formation constants. Second, a similar study is led in the presence of nonionic micelles. It underlines a modification of the apparent equilibrium constants in micellar medium and demonstrates that the structure of the complexes is slightly modified in the presence of micelles. This thermodynamic and structural study is applied to modelize the evolution of the extraction yields of Cu(II) by the micelles as a function of pH and to identify the complexes extracted in the micelles. The effects of the chain length of the ligand (C3T vs C8T) on the solubilization properties are put into relief and discussed. Anionic species are proved to be more incorporated in the nonionic micelles than the cationic species. The extracting system constituted of octylamidotartaric acid (CsT) solubilized in nonionic micelles of Brij 58 is demonstrated to be very efficient for the extraction of Cu(II) by MEUF, this technique being an interesting green alternative to traditional solvent extraction.

Quantitative Analysis of the Interactions of Metal Complexes and Amphiphilic Systems: Calorimetric, Spectroscopic and Theoretical Aspects

“…Analysis of the binding mechanism, obtained by carefully splitting the contributions, provided a picture where the Ni 2+ + HL NiHL 2+ step occurs in both pseudo-phases, whereas the Ni 2+ + L − NiL + step in water is replaced by NiOH + + HL NiL + when in SDS [94]. A similar procedure was applied in the case of the Cu 2+ /tartaric acid systems in the presence of non-ionic Brij 58 micelles [95]; this detailed thermodynamic study indicated that the structures of the complexes incorporated in the micelles and the species-distribution diagrams are modified if compared to water and allowed to model the evolution of the extraction yields of Cu 2+ ions by the micelles as a function of pH.…”

Metal ion extraction in microheterogeneous systems

“…Ultrafiltration experiments demonstrated that anionic complexes may be associated to the micelles and allows copper extraction [67].…”

Correlation of Filtration Behavior of Chiral and Racemic Mg(tartrate) Suspensions with Morphological Differences and Observation of Cross Structure in a Metal Organic Framework

“…Tartaric acid and its derivatives have been of great interest in chemistry ever since the chiral, racemic and meso forms of the acid were discovered by Louis Pasteur. , The various isomers have been utilized in the formation of metal complexes, in asymmetric synthesis, − and in enantioseparations …”

“…Tartaric acid and its derivatives have been of great interest in chemistry ever since the chiral, racemic and meso forms of the acid were discovered by Louis Pasteur. 1,2 The various isomers have been utilized in the formation of metal complexes, 3 in asymmetric synthesis, 4−6 and in enantioseparations. 7 Dibasic acids have been employed extensively in the preparation of a wide range of coordination polymers 8 and metal organic framework (MOF) structures.…”