Ion-size recognition of Group 13 metals (Al and In) with modified β-diketones, 3- phenylpentane-2, 4-dione (α-phenylacetylacetone, HL) and 1, 2-diphenylbutane-1, 3-dione (α-phenylbenzoylacetone, HL), has been studied by the liquid–liquid extraction method and compared with that of pentane-2, 4-dione (acetylacetone, HL)