A comparison of complexation of Li+ ion with macrocyclic ligands 15-crown-5 and 12-crown-4 in binary nitromethane–acetonitrile mixtures by using lithium-7 NMR technique and ab initio calculation

Aerosol Cross-Linked Crown Ether Diols Melded with Poly(vinyl alcohol) as Specialized Microfibrous Li+ Adsorbents

“…Thus, the large discrepancies between q CE and q theo at C o < 35 mg L –1 is mainly due to the unsaturated states of CEs given the limited availability of Li + and not because of 2:1 complexation or inaccessibility of CEs to Li + . Furthermore, a 2:1 complexation requires close interaction and special orientation between two CEs . Thus, it is likely to occur only in systems with CEs that are free to move, like in liquid–liquid extraction .…”

“…Furthermore, a 2:1 complexation requires close interaction and special orientation between two CEs. 64 Thus, it is likely to occur only in systems with CEs that are free to move, like in liquid−liquid extraction. 65 However, this is not the case in CE/PVA MFs because the neighboring CEs are distanced (l…”

NMR study of the stoichiometry and stability of complexation reaction between Mg2+, Ca2+, Sr2+ and Ba2+ ions and 60-crown-20 in binary acetonitrile solvent mixtures

“…From the data in Table 1, it is obvious that the stability of all 60C20 complexes increased in the order of acetonitrile-D 2 O \ acetonitrile \ acetonitrile-nitromethane. It is well known that the Gutmann donors number of solvent [23] is an important factor in complexation reactions [17][18][19]. It should be noted that acetonitrile and nitromethane possess similar dielectric constants (i.e., e AN = 37.5, e NM = 35.6), but have quite different donors number (i.e., DN AN = 14.1 and DN NM = 2.7) 23 .…”

“…Various techniques have been used to study the complexation of a range of ligands with different cations in a variety of nonaqueous and mixed solvents [14][15][16]. Among the spectroscopic and electrochemical methods used for the study of metal ion-crown ether complexes, NMR spectroscopy has been found to act as a very sensitive technique for studying the changes in the immediate chemical environment of metal ions in solutions [17,18]. To the best of our knowledge there are no report on the complexation reaction between 60-crown-20 (60C20) and metal ions, we attempted to study the complexation reaction of 60C20 with Mg 2?…”

Thermodynamic study of crown ether–lithium/magnesium complexes based on benz-1,4-dioxane and its homologues

“…For example, the complex stability with benzo-15-crown-5, 12crown-4, and 14-crown-4 CEs adsorbers have shown excellent complexation properties with Li + ; however, complexations with Mg 2+ and Na + were also possible. 18,[24][25][26][27][28][29][30][31][32] To selectively extract Li + from aqueous resources, the complexation behavior of Li + and the other metal ions is of great importance. Especially the complexation properties of Li + and Mg 2+ are of great interest since they have almost the same ion diameter in aqueous solution.…”