Extraction Behavior of Di-μ-oxo-bis[oxomolybdenum(V)] with 2-Methyl-5-octyloxymethyl-8-quinolinol

Abstract

Abstract Binuclear oxomolybdenum(V), Mo2O42+, was quantitatively extracted with 0.01 mol dm−3 2-methyl-5-octyloxymethyl-8-quinolinol (HMO8Q) in chloroform at pH 2.3 and isobutyl methyl ketone at pH 1.0—3.9. To elucidate the extraction equilibrium, the effect of the pH as well as the HMO8Q and molybdenum(V) concentration on the distribution ratio of Mo2O42+ was studied. The extracted complex was found to be Mo2O4(MO8Q)2; the extraction constants (Kex) were determined to be 100.15 and 101.57 in benzene and chloroform, respectively. These values were lower than Kex = 103.26 obtained in the Mo2O42+-5-octyloxymethyl-8-quinolinol–chloroform system, suggesting a steric effect of the methyl group at the 2-position. In the presence of trioctylphosphine oxide (TOPO) a great enhancement of molybdenum(V) extraction was found and could be ascribed to the formation of an adduct, Mo2O4(MO8Q)2(TOPO).