Three-Dimensional Open Frameworks Based on Cobalt(II) and Nickel(II) <i>m</i>-Pyridinecarboxylates

Three-dimensional open frameworks [Co2(nicotinate)4(μ-H2O)]·CH3CH2OH·H2O, 1, and [Ni2(nicotinate)4(μ-H2O)]·CH3CH2OH·H2O, 2, were obtained by hydro(solvo)thermal reactions between 3-cyanopyridine and cobalt(II) nitrate and nickel(II) perchlorate, respectively. Both 1 and 2 exhibit complicated 3-D structures based on [M2(nicotinate)4(μ-H2O)] (M = Co or Ni) building blocks and possess open channels that are occupied by removable solvent molecules. 3-D open frameworks [M2L4(μ-H2O)]·HL·(H2O)x (where M = Co, x = 2, 3, and M = Ni, x = 1, 4, and L = trans-3-(3-pyridyl)acrylate) were similarly prepared with trans-3-(3-pyridyl)acrylic acid in place of 3-cyanopyridine. Compounds 3 and 4 are isostructural and exhibit network topologies similar to that of 1 with open channels occupied by disordered trans-3-(3-pyridyl)acrylic acid and water guest molecules. Crystal data for 1: triclinic space group P1̄, a = 10.534(1) Å, b = 11.907(1) Å, c = 14.046(1) Å, α = 106.645(1)°, β = 101.977(1)°, γ = 112.078(1)°, and Z = 4. Crystal data for 2: tetragonal space group P4/ncc, a = 20.089(1) Å, c = 14.016(1) Å, and Z = 4. Crystal data for 3: monoclinic space group C2/c, a = 14.082(2) Å, b = 15.278(2) Å, c = 18.537(2) Å, β = 105.360(2)°, and Z = 2. Crystal data for 4: monoclinic space group C2/c, a = 14.082(1) Å, b = 15.250(1) Å, c = 18.606(1) Å, β = 106.747(1)°, and Z = 2.