Structure and anion-exchange of a three-dimensional Ag(I) metal–organic framework

A coordination polymer [Ag4(C12H12N6)3](ClO4)4(H2O)4 (1), was achieved via the self-assembly of AgClO4 with ligand 2,5-bis(pyrazinyl)-3,4-diaza-2,4-hexadiene (L1). The structure of compound 1 is a 3D metal–organic framework that consists of the circular helicate Ag3 (L1)3 secondary building blocks (SBUs). Each image is capped at its every exo-monodentate pyrazinyl terminal by the unusual hexa-coordinated Ag(I) centers. Being filled within the cavities, the image anions could be exchanged reversibly with image in the solid state.