Cation-directed assembly of polyrotaxane and polycatenane

Abstract

Divalent metal (Pb or Zn) coordination polymers containing 1,4-bis(4-pyridyl)piperazine (bpp) and 4,4'-sulfonyldibenzoic acid (H(2)sdb) exhibit different interlocked topologies. In [Pb-2(sdb)(2)(bpp)](n) (1), two Pb(II) generate Pb-2(sdb)(2) metallacycles connected by bpp ligands, leading to the formation of a 1D + 1D -> 1D polyrotaxane. In contrast, in {[Zn-2(sdb)(2)(bpp)(2)]center dot 2DMA}(n) (2), tetrameric metallacycles Zn-4(sdb)(4) are interlocked, generating 1D polycatenated chains in a parallel manner and are further pillared by bpp ligands to build a 3D framework.