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Synthesis and characterization of lithium and magnesium complexes based on [EDTA][PEG400] 2 and [EDTA] 3 [PEG400] 7

2002; Wiley; Volume: 203; Issue: 9 Linguagem: Inglês

10.1002/1521-3935(200206)203

1521-3935

Vito Di Noto, Vera Münchow, Michele Vittadello, Jean Claude Collet, Sandra Lavina,

Ionic liquids properties and applications

Two distinct types of host polymers, [EDTA]3-[PEG400]7 and [EDTA][PEG400]2, consisting of polyether chains linked together by ethylenediaminetetraacetic acid (EDTA) chelating units, were synthesized from EDTA acetate esters and poly(ethylene glycol) 400 (PEG400). Their structures were revealed by analytical analyses, viscosimetric measurements, NMR and FT-IR studies. Direct dissolution of δ-LiCl and δ-MgCl2 in these prepared host polymers resulted in the following complexes: [EDTA]3-[PEG400]7/(LiCl)6.39, [EDTA]3[PEG400]7/(MgCl2)8.23, [EDTA]3[PEG400]7/(LiCl)6.39(MgCl2)6.16, [EDTA][PEG400]2/ (LiCl)2.26, [EDTA][PEG400]2/(MgCl2)1.98 and [EDTA]-[PEG400]2/(LiCl)2.26(MgCl2)1.98. Mid- and far-FT-IR spectroscopic studies revealed the following properties for all six complexes: a) the polyether chains are in the trans–gauche–trans conformation; b) the Mg2+ ion could be hexa- or heptacoordinated to the chelating sites of EDTA; c) the Li+ ion is preferentially coordinated by the oxygen atoms of the residual acetate groups and polyether moieties. Results of conductivity measurements at room temperature indicated that the proposed Mg products might be very useful for the development of electrochemical transducers for measuring water hardness. Esterification of EDTA dianhydride with PEG400; (2): Synthesis of the complexes (MXn = LiCl/MgCl2).