Synthesis and structure of a novel copper (II) nitrate complex of 2,4-dioxo-4-phenylbutanoic acid

2,4-Dioxo-4-phenylbutanoic acid, 1, was synthesized as a biproduct of the attempted synthesis of 1,6-bisphenyl-1,3,4,6-hexanetetrone. Crystals of Cu(H2O)(bipy) (L)]Cu(bipy)(L)(NO3)] (H2O)(NO3) (L = 2,4-dioxolato-4-phenylbutanoic acid and bipy = 2,2′-bipyridine), 2, were grown by slow evaporation of a solution of Cu(NO₃)₂·3 H₂O, 2,2′-bipyridine, and 1 in a mixture of ethanol and water. The compound crystallized in the triclinic space group P-1 and is made up of two distinct molecular units each with approximately square pyramidal geometry: a = 10.663(2) ?, b = 13.275(3) ?, c = 15.071(3) ?, α = 80.26(3)°, β = 74.13(3)°, γ = 89.12(3)°. The copper ions are chelated by molecules of 1 and molecules of bipyridine. The molecular units are arrayed in rows held together by pi-stacking interactions and hydrogen bonding.