Reaction of gallium and indium with 4-(2-Thiazolylazo) resorcinol.
Gallium is shown to react with TAR to form 1:1 and 1:2 Ga:TAR species, elucidation of the nature of which is complicated by hydrolysis. The species GaR(+) and GaHR(OH)(+), where H(2)R is the free reagent, occur at pH 2.7-4.8 for solutions that are equimolar or contain excess of metal ion; GaHR(2+) occurs at pH 2.13-2.86 with excess of metal ion. A 1:2 complex, probably GaR(2)(-), exists in 30% aqueous ethanol medium at pH approximately 5 if excess of ligand is present. The utility of the reaction for analysis is severely limited by the large number of interfering elements. Indium reacts similarly, forming a In RH(2+) complex which is converted into the 1:2 complex by excess of reagent at pH 4.6.
Langová-Hnilicková
M
M
Department of Analytical Chemistry, The University, Brno, Czechoslovakia.
Sommer
L
L