Self-Assembly of Metal-Organic Coordination Polymers Constructed from a Versatile Multipyridyl Ligand: Diversity of Coordination Modes and Structures

Six d(10) metal metal-organic coordination polymers, [Zn-2(HtPim)(2)(tp)(2)]center dot 2H(2)O}(n) (1), {[Cd-3(H(0.5)tpim)(4)(pa)(2)(H2O)(2)]center dot 5H(2)O)(n) (2), [Zn(Htpim)(2)(Htma)](n) (3), {[Zn-4(Htpim)(4)(ip)(4)]center dot 2H(2)O}(n) (4), [Cd(Htpim)(ca)](n) (5), and {[Cd-4(Htpim)(2)(D-ca)(4)(H2O)(2)]center dot 5H(2)O)(n) (6) (Htpim 2,4,5-tri(4-pyridyl)-imidazole, H(2)tP = terephthalic acid, H(2)pa = phthalic acid, H(3)tma = trimesic acid, H(2)ip = isophthalic acid, H(2)ca = racemic camphor acid, D-H(2)ca = D-camphor acid), have been prepared and structurally characterized. In all complexes, the rigid ligand Htpim, exhibits different coordination modes and leads to the formation of various architectures. Complex 1 shows a two-dimensional (21)) network with (6,3) topology, where hydrogen-bonding interactions further link these sheets to a three-dimensional (3D) supramolecular structure. Complex 2 exhibits a 2D layer with (5(3))(5(4)) network topology. Complex 3 is a corrugated 2D layer with (4,4) topology, and the separated layers are connected through weak pi-pi stacking interactions to generate a 3D supramolecular architecture. Complex 4 is a rhombic 2D layer with (4,4) topology, and the 3D overlapped array is formed by hydrogen-bonding and pi-pi stacking interactions. A 3D diamondoid framework with 4-fold interpenetration is found in 5. Complex 6 contains a complicated 3D framework, and the vacancy is occupied by the guest water molecules. Their luminescent properties have been investigated in the solid state.