New inorganic-organic hybrid supramolecular architectures generated from 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene

Two new metal coordination polymers with interesting supramolecular architectures, [Mn(H₂O)₄-(L¹)] _n(ClO₄)_2n·2nL¹(1) and [Ag(L¹)(NO₃)]_n (2) [L¹ = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene], have been synthesized and characterized structurally. Complex 1 exhibits a novel supramolecular layer architecture sustained by the concurrence of coordination bonds, hydrogen bonds, and π-π stacking interactions: the Mn(II) ions are coordinated by water molecules and the bridging μ₂-L¹ ligands to yield one-dimensional (1D) zigzag [Mn(H₂O)₄(L¹)] _n coordination chains; the free L¹ ligands are hydrogen bonded to half of the coordinated water molecules and form π-π stacking triads with the bridging ligands, generating three-strand supramolecular ribbons; and the perchlorate ions form hydrogen bonds with the remaining coordinated water molecules, interlinking the ribbons into an unusual tripledecked supramolecular layer. In complex 2, each Ag(I) ion is tetracoordinated by two μ₂-L¹ and two μ₂-nitrate ligands. The μ₂-L¹ ligands connect the metal ions into infinite 1D helix-like AgL¹ chains, and the μ₂-nitrate ions interlink the chains into undulate coordination layers. C-H⋯O weak hydrogen bonds exist between neighboring layers in 2.