Syntheses and characterization of dinuclear and tetranuclear AgI supramolecular complexes generated from symmetric and asymmetric molecular clips containing oxadiazole rings

A new asymmetric ligand, 5-{3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]phenyl}-2-(pyridin-3-yl)-1,3,4-oxadiazole (L5), which contains two oxadiazole rings, was synthesized and characterized. The assembly of symmetric 2,5-bis(pyridin-3-yl)-1,3,4-oxadiazole (L1) and asymmetric L5 with AgCO2CF3 in solution yielded two novel AgI complexes, namely catena-poly[[di-μ-trifluoroacetato-disilver(I)]-bis[μ-2,5-bis(pyridin-3-yl)-1,3,4-oxadiazole]], [Ag2(C2F3O2)2(C12H8N4O)2] n or [Ag2(μ2-O2CCF3)2(L1)2] n (1), and bis(μ3-5-{3-[5-(4-methylphenyl)-1,3,4-oxadiazol-2-yl]phenyl}-2-(pyridin-3-yl)-1,3,4-oxadiazole)tetra-μ3-trifluoroacetato-tetrasilver(I) dichloromethane monosolvate, [Ag4(C2F3O2)4(C22H15N5O2)2]·CH2Cl2 or [Ag2(μ3-O2CCF3)2(L5)]2·CH2Cl2 (2). Complex 1 displays a one-dimensional ring–chain motif, where dinuclear Ag2(CF3CO2)2 units alternate with Ag2(L1)2 macrocycles. This structure is different from previously reported Ag–L1 complexes with different anions. Complex 2 features a tetranuclear supramolecular macrocycle, in which each ligand adopts a tridentate coordination mode with the oxadiazole ring next to the p-tolyl ring coordinated and that next to the pyridyl ring free. Two L5 ligands are bound to two Ag1 centres through two oxadiazole N and two pyridyl N atoms to form a macrocycle. The other two oxadiazole N atoms coordinate to the two Ag2 centres of the Ag2(O2CCF3)4 dimer. Each CF3CO2 − anion adopts a μ3-coordination mode, bridging the Ag1 and Ag2 centres to form a tetranuclear silver(I) complex. This study indicates that the donor ability of the bridging oxadiazole rings can be tuned by electron-withdrawing and -donating substituents. The emission properties of ligands L1 and L5 and complexes 1 and 2 were also investigated in the solid state.

Homodimerization driven self-assembly of glycoluril molecular clips with covalently immobilized poly(ε-caprolactone)

We synthesized the first glycoluril clip–polymer conjugate, which forms a novel type of multilayered self-assembly.

Complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives

The complexation of molecular clips containing fragments of diphenylglycoluril and benzocrown ethers with paraquat and its derivatives has been studied both in solution and in the solid state. In this paper we studied the influence of the crown ether ring size and the nature of the substituents at the nitrogen atoms of the paraquat derivatives on the composition and stability of these complexes.

Dimeric molecular clips based on glycoluril

Phenylene-bridged glycoluril dimers are used for the construction of supramolecular host molecules with high affinity towards methylviologen in water.