138220-69-6Relevant articles and documents
PHOSPHORUS-CONTAINING PODANDS. 7. COMPLEXING PROPERTIES OF ortho-DIPHENYLPHOSPHINYL-SUBSTITUTED DIPHENYL ETHERS OF OLIGOETHYLENE GLYCOLS WITH RESPECT TO ALKALI-METAL CATIONS
Evreinov, V. I.,Baulin, V. E.,Vostroknutova, Z. N.,Safronova, Z. V.,Krashakova, I. B.,et al.
, p. 1759 - 1766 (1991)
Stability constants of complexes of alkali-metal cations with oligoethylene glycol diethers RO(CH2CH2O)nR (n = 1-5), where R = 2-Ph2P(O)C6H4 and 2-Ph2(O)-4-t-BuC6H3P, have been determined conductometically in a tetrahydrofuran-chloroform mixture (4:1 by volume).The dependence of complexing ability on a number of monopodand donor centers for Li+ and Na+ has multiple extrema.For K+, Rb+, and Cs+ the complexing abilities steadily increase with the length of the ligand polyether chain.Monopodands based on triethylene glycol and its pyrocatechol analog are highly effective (log K = 6.7-7.0) with respect to Li+.The synthesis of ligands with a lipophilic tert-butyl substituent in the terminal group is described.
