Observations on some potentially asymmetric gallium(III) compounds

Abstract

Attempts to resolve the potentially asymmetric tris(oxalato)gallate(III) ion by fractional crystallization, precipitation, or extraction techniques involving its salts with l-strychnine, l-quinine, d-cinchonine, and d-tris(ethylenediamine)-cobalt(III) have been unsuccessful. Inasmuch as the tris(oxalato)-gallate(III) ion in aqueous solution gives immediate precipitation of calcium oxalate with calcium ion and undergoes essentially instantaneous exchange with oxalate ion containing carbon-14, it is concluded that the ion is probably too unstable to retain asymmetry long enough to permit resolution. Negative results have been obtained in attempts to resolve the ethylene-diaminetetraacetatoaquogallate(III) ion by fractional extraction of its l-brucine salt. Tris(ethylene-diamine)cobalt(III) ion has been found to precipitate the tris(oxalato)gallate(III) ion quantitatively without precipitating oxalate ion.