Seven entangled coordination polymers assembled from triphenylamine-based bisimidazole and dicarboxylates: interpenetration, self-penetration and mixed entanglement

Abstract

Seven new entangled coordination polymers, namely, [Zn(sdc)(bita)] (1), [Zn(1,4-ndc)(bita)] (2), [Zn₂(bdc)₂(bita)₂] (3), [Zn₂(sda)₂(bita)₂] (4), [Cd(odc)(bita)]·0.5H₂O (5), [Cd₂(bpdc)₂(bita)₂] (6) and [Cd₃(bpdc)₃(bita)₂]·2DMF (7) [bita = 4,4′-bisimidazyltriphenylamine, H₂sdc = 4,4′-sulfonyldibenzoic acid, 1,4-H₂ndc = naphthalene-1,4-dicarboxylic acid, H₂bdc = 1,4-benzenedicarboxylic acid, H₂odc = 4,4′-oxybisbenzoic acid, H₂sda = 4,4′-stilbenedicarboxylic acid, H₂bpdc = biphenyl-4,4′-dicarboxylic acid], have been synthesized and structurally characterized. Compound 1 exhibits a 2D → 2D polycatenane of three-fold interpenetrated sql networks. Compound 2 displays a four-fold interpenetration of a dia network in a [2 + 2] mode. Compound 3 features both polyrotaxane and polycatenane composed of two interlocked sets of hcb network. Compound 4 shows three-fold interpenetration of a pcu network. Compound 5 presents unusual two-fold interpenetration of a self-penetrating framework with (4²·6·8³) topology. Compound 6 displays a 2D → 3D polycatenane of three-fold interpenetrated sql networks. Compound 7 exhibits an unusual self-penetrating framework with (4²⁵·6³) topology. The thermal stabilities and photochemical properties of these compounds have also been studied.