ISSN:
1573-9171
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The complex-forming reactivity of mono- and disubstituted ethylenediphosphine dioxides of the general formula Ph2P(O)CH2C(R1R2)P(O)Ph2, and of a tetraphosphorylated monopodand, ortho-bis[4,5-bis(diphenylphosphinyl)-pentoxy]benzene, relative to alkali metal cations have been determined conductometrically in THF-CHCl3 medium (4:1). Introduction of alkyl substituants in the ethylene bridge of tetraphenylethylenediphosphine dioxide increases its Li/Na selectivity; maximum Li/Na selectivity equal to 40 is observed for the dimethyl-substituted tetraphenylethylenediphosphine dioxide derivative. Among the ligands examined herein the hexadentate tetraphosphoryl-containing monopodand ortho-bis[4,5-bis(diphenylphosphinyl)pentoxy]benzene was found to be the most effective complex-forming agent with respect to lithium (logβ=6.0), with a high Li/Na selectivity value equal to 40. The syntheses of 1,1-dimethyltetraphenylethylenediphosphine dioxide and of ortho-bis[4,5-bis(diphenylphosphinyl)pentoxy]benzene are described.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00960346
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