Heterochiral-to-Homochiral Structural Transformation in Metallosupramolecular Ionic Crystals.

ABSTRACT

Here, we report a unique transformation from heterochiral to homochiral structures in ionic crystals composed of complex cations and complex anions. Treatment of an anionic AuI3CoIII2 complex, ΛΛ-[Au3Co2(d-pen)6]3- ([1]3-; H2pen = penicillamine), with M = MnII, CoII, NiII, ZnII in water in the presence of 1,10-phenanthroline (phen) commonly gave ionic crystals formulated as [M(phen)2(H2O)2][Na(H2O)6][{M(phen)2(H2O)}(1)]3 (2M), in which [M(phen)2(H2O)2]2+ and [M(phen)2(H2O)]2+ adopt Δ and Λ configurations, respectively. While 2Co, 2Ni, and 2Zn were all stable in each mother liquor, 2Mn was converted to [Mn(phen)3]3[1]2·phen (3Mn) containing the Λ configurational [Mn(phen)3]3+ under the same conditions. 3Mn showed a water adsorption capacity higher than that of 2Mn, despite its lower porosity of crystal.