A homochiral network constructed by supramolecular packing of 2D chiral bilayer: synthesis, structure and property of metal(ii) complex based on achiral 3,3′,4,4′-oxydiphthalate and coligand

Abstract

Using achiral 3,3′,4,4′-oxydiphthalic acid (H₄ODPA) and coligands, four metal(II) complexes formulated as Ni₂(ODPA)(4,4′-bpy)₂(H₂O)₄·H₂O (bpy = bipyridine) (1), Cu₄(H₂ODPA)₄(2,2′-bpy)₄(H₂O)₂·2H₂O (2), Co₃(HODPA)₂(2,2′-bpy)₃(H₂O)₁₀·2H₂O (3) and Zn₂(H₂ODPA)(L)₂·6H₂O (HL = gatifloxacin) (4) have been synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 shows a uninodal 3-connected chiral 2D bilayer with {8².10} topology. Packing of the 2D bilayer leads to the homochiral architecture of complex 1. Complexes 2 and 3 are tetranuclear Cu(II) and mononuclear Co(II) complexes, respectively. Complex 4 shows a chain-like structure. Complex 1 shows strong CD signal, and complexes 2–4 are achiral. The twisted 4,4′-bpy plays an important role in the formation of the chiral complex 1. The supramolecular packing in complex 1 accounts for the chiral space group of the structure. The four complexes show different UV-vis absorption and photoluminescence properties as well as different thermal stability.