Supramolecular inclusion of a pillared double-layered host by an anion-directed second-sphere coordination

In this paper, we have illustrated the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with varieties of guest molecules. A flexible molecule N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine (L1) bearing doubly protonated H-bond donors was designed, capable of forming N–H…Cl hydrogen bonds with a crystallographically unique chloride anion, to construct an anion-directed ligand. The pillared double-layered host framework was constructed by an anion-directed ligand and primary coordination sphere CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interactions. A variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of novel supramolecular inclusion solids: L1]·4H]⁺·CoCl₄]^2 ? ·2Cl^? ·1.5C₈H₈O₂]·0.25CH₃OH] (1) and L1]·4H]⁺·CoCl₄]^2 ? ·2Cl^? ·1.5C₁₂H₂₀O₄]·0.5CH₃OH] (2).

We have presented herein the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with a variety of guest molecules. A novel type of a pillared double-layered host framework was constructed by a second-sphere coordination between the anion-directed ligand (L1 = N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine) and CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interaction, and a variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of supramolecular inclusion solids: L1]·4H]⁺·CoCl₄]^2 ? ·2Cl^? ·1.5C₈H₈O₂]·0.25CH₃OH] (1) and L1]·4H]⁺·CoCl₄]^2 ? ·2Cl^? ·1.5C₁₂H₂₀O₄]·0.5CH₃OH] (2)