Structure and thermal stability of a novel 2-D layered copper(II) coordination polymer with the bidentate ligand 1,2,4-Triazol-5-one

Single crystals of {[Cu(TO) ₂(H ₂O)2](NO ₃) ₂} _n (TO: 1,2,4-triazol-5-one) were grown by slow evaporation from aqueous solution. It crystallizes in the orthorhombic space group Pbca, with a = 7.082(1), b = 10.285(1), c = 17.911(3) Å, V = 1304.6(3) Å ³, Z = 4. The Cu ^II distorted octahedra are bridged by bidentate TO ligands into infinite 2-D interlaced rhombic grid-like network planes, {[Cu(TO) ₂(H ₂O) ₂] ²⁺} _n. Hydrogen bonds, electrostatic interactions, and weak van der Waals' forces assemble these planes and the NO ₃ ^- anions to a layered structure. The title compound decomposes at 153.4°C to the final products, Cu(CN) ₂ and CuO.