PHOSPHORUS-CONTAINING PODANDS. 4. EFFECT OF POLYETHER CHAIN LENGTH OF OLIGOETHYLENE GLYCOL BIS(ORTHO-DIPHENYLPHOSPHINYLMETHYL)PHENYL ETHERS ON THEIR COMPLEX-FORMING AND SELECTIVE PROPERTIES WITH RESPECT TO ALKALI METAL CATIONS

Article abstract of DOI:10.1007/BF00957771

Alkylation of o-(diphenylphosphinylmethyl)phenol by oligoethylene glycol ditosylates leads to a series of acyclic polyether complexing agents (podands) with phosphinylmethylphenyl terminal groups.A conductometric method in tetrahydrofuran-chloroform (4:1 by volume) has been used to determine the stability constants of the pobands with alkali metal 2,4-dinitrophenoxides.Several of the prepared ligands exhibited a high Li/Na, Na/K, and Li/K selectivity.For lithium and sodium cations, the curve of complex-forming ability against the overall number of donor centers in the structure of the podand has a maximum for the case of tetraethylene glycol bis(o-diphenylphosphinylmethyl)phenyl ether.For lithium cations, this compound surpasses the crown ethers in terms of its effectiveness and is the most powerful of the phosphoryl-containing complexing agents.For potassium, rubidium, and cesium cations, the complex-forming ability increases with increase in the number of oxygen donor centers in the polyether chain of the ligand.