556-65-0Relevant articles and documents
Brown, A. W.,Audrieth, L. F.
, p. 917 - 925 (1927)
Complexation and Solvent Extraction of Lithium Salts with 2,3,6,7,9,10-Hexahydro-5H-1,4,8,11-benzotetraoxacyclotridecin (Benzo-13-crown-4)
Olsher, Uriel,Jagur-Grodzinski, Joseph
, p. 501 - 505 (1981)
Solubility measurements were conducted in order to compare the affinity towards lithium salts of several 12- to 16-membered ring 'crown' ethers.The 13-membered ring benzo-13-crown-4 (L1) was found to be the most effective complexing agent for lithium among the investigated macrocyclic ethers.The effect of counter ions on the solubility was found to be OH(1-) 1 extract lithium salts selectively from aqueous solutions.In the latter solvent selectivity factor γ(Li(1+)/M(n+)) was found to be 2.5, 44, 216, and 355 for Na(1+), K(1+), Mg(2+), and Ca(2+) respectively.Hydrogen-1 n.m.r. measurements for the solutions of the lithium complexes of L1 indicate that a planar conformation of the quadridentate macrocyclic ring seems to be favoured in the complexed L1. The 1 : 1 complexes have been found to be dominant in all investigated solvent systems.However, in methylene chloride and in nitromethane the 2 : 1 'sandwich' type complexes could also be detected.The stability constants of the complexes were found to increase in order of decreasing donicity of the solvent media.
Complexation of phosphoryl-containing mono-, bi- and tri-podands with alkali cations in acetonitrile. Structure of the complexes and binding selectivity
Solov'ev, Vitaly P.,Baulin, Vladimir E.,Strakhova, Nadezhda N.,Kazachenko, Vladimir P.,Belsky, Vitaly K.,Varnek, Alexandre A.,Volkova, Tatiana A.,Wipff, Georges
, p. 1489 - 1498 (2007/10/03)
We present experimental and theoretical studies on new ionophores (L) which possess a high complexation ability for Li+or Na+cations. Four tri-podands(R1-O-C2H4-)3N[R 1 = -CH2-P(O)Ph2(P1), -C2H4-P(O)Ph2 (P2), -o-C6H4P(O)Ph2 (P3) and -o-C6H4-CH2-P(O)Ph2 (P4)], one bi-podand (R2-O-C2H4-)2N-CH3 [R2 = -o-C6H4-CH2-P(O)Ph2 (P5)] and one mono-podand [R2-O-(CH2-CH2-O)3R2 (P6)] containing phosphine oxide terminal groups have been synthesised. Stability constants, enthalpies and entropies of their complexation with lithium, sodium and potassium thiocyanates have been determined in acetonitrile at 298 K by a calorimetric titration technique. We find that tri-podands form a variety of complexes [(M+)3L, (M+)2L, M+L and M+L2)], whereas the bi- and mono-podand form only M+L complexes with Li+ and Na+, and M+L and M+L2 complexes with K+. Formation of poly-nuclear (M+)nL complexes of tri-podands in solution has been confirmed by electro-spray mass spectrometry. At relatively small concentrations of the ligand (CL0)S P1 binds Na+ much better than Li+, whereas P4 and P5 display a remarkable Li+/Na+ selectivity; at large CL0 the complexation selectivity decreases. X-Ray diffraction studies performed on monocrystals of complexes of NaNCS with tri-podands P2 and P3 show that Na+ is encapsulated inside a 'basket-like' pseudocavity, coordinating all donor atoms of the tri-podand. Molecular dynamics simulations on P2, P3 and P4 and on their 1:1 complexes with M+ in acetonitrile solution suggest that the structures of M+L complexes in solution are similar to those found for P2 and P3 complexes in the solid state.
