Entangled 3D metal-organic architectures from the self-assembly of mixed ligands and transition-metal ions

Two new entangled 3D metal-organic frameworks, [Ni2(TP)2(BPP) 2(H2O)2]n (1) and {[Co(TP)(BPP)]4·6H2O}n (2), have been hydrothermally synthesized with mixed ligands of terephthalate (TP) and 1,3-bis(4-pyridyl)propane (BPP) and transition-metal nitrates. Both compounds were characterized by elemental analysis, TGA, IR and single crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pnna with a = 18.350(4), b = 13.447(3), c = 16.394(3) Å, V = 4045.2(14) Å3, Z = 4, R1(wR2) = 0.0481(0.1072). Compound 2 crystallizes in the triclinic space group P1¯ with a = 11.860(2), b = 18.029(4), c = 20.069(4) Å, α = 106.94(3), β = 92.27(3), γ = 97.02(3), V = 4061.2(14) Å3, Z = 2, R1(wR2) = 0.0895(0.2279). Compound 1 contains a new type of 1D zigzag ladders which are further interlocked with the other two identical ones, forming a 3D polycatenated framework. Compound 2 displays a new 3D “inclined” interpenetration architecture based on 2D undulated layers.