1D Coordination Polymer from Tetraaza Macrocyclic Nickel(II) Complex and 1,2,3,4-Cyclobutanetetracarboxylic Acid

The self assembly of Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo14,4,0^1.18,0^7.12]docosane) and 1,2,3,4-cyclobutanetetracarboxylic acid (H₄cbtc) acid generates a 1D coordination and 2D hydrogen-bonded polymer Ni(L)(H₂cbtc)₂·3H₂O] _n (1). Complex 1 is characterized by X-ray crystallography, spectroscopy and magnetic susceptibility. Each nickel(II) ion has a distorted octahedral coordination environment with the four secondary amines of the macrocycle in which two carboxylate anions of the H₂cbtc^2? ligand have assembled around each nickel center. The compound crystallizes in the triclinic system P-1 with a = 9.715(3) Å, b = 12.891(5) Å, c = 13.903(6) Å, α = 72.64(2)°, β = 75.70(3)°, γ = 73.27(3)°, V = 1566.6(10) ų, Z = 2. The electronic spectrum of 1 indicates a high-spin octahedral environment. The magnetic behavior of 1 reveals a weak intramolecular antiferromagnetic interaction with J = ?1.23(1) cm^?1.