Self-Organization of 𝐊⁺-Crown Ether Derivatives into Double-Columnar Arrays Controlled by Supramolecular Isomers of Hydrogen-Bonded Anionic Biimidazolate Ni Complexes

Figure 3

Structural view of each hexagonal cavity for crystals 1–5. (a) The structure of the hexagonal cavity of 1 is constructed from nondistorted hydrogen bond connections of six [Ni(Hbim)₃]⁻ molecules with alternating ΔΛ−ΔΛ−ΔΛ sequences of the Δ (red sphere) and Λ (blue sphere) optical isomers and includes two [K-DCH(18-ccrown-6)]⁺. The frameworks of K⁺-crown ether derivatives and MeOH molecules are represented by the green ball-and-stick lines. The potassium and nickel (II) ions are drawn with yellow and magenta spheres, respectively. ((b) and (e)) The hexagonal cavities of 2 and 5, which are represented by H-bonded connections of the ΔΔΔ−ΛΛΛ sequence with the distorted connection of the same optical isomers, include two [K-MCH(18-crown-6)]⁺ and two [K-cryptand]⁺ molecules, respectively. (c) The hexagonal cavity of 3 that includes [K-MZB(18-crown-6)]⁺ is constructed from a sequence similar to that of 1 (ΔΛ−ΔΛ−ΔΛ), although the hydrogen bonding connections are distorted. (d) The hexagonal cavity of 4 that includes [K-cryptand]⁺, which is also a polymorph of 5, is constructed from the ΔΛ−ΔΛ−ΔΛ sequence.

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(b)

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