Structural Investigation of Metal-Organic Cu(II) Coordination Frameworks Constructed from N-donor and α, ω-Dicarboxylate Ligands by One Pot Synthesis: Zigzag Strands,Layered Networks and Its Interaction with Lattice Water Molecules

Abstract  

Two metal organic frameworks involving α, ω-dicarboxylates and 2,2′-bpy, Cu(2,2Bpy)(μ-adipate-H2)] _n ·2·H₂O 1 and Cu₂ (2,2′-bpy)₂(μ-adipate-H)₂(μ-adipate-H2)]·3H₂O 2 have been synthesized by one pot reaction and structurally characterized. Pentacoordinated Cu(II) zigzag polymeric chain of 1 is composed of linking the adjacent Cu(2,2′-bpy)(H₂O) units through terminal craboxylate oxygens of two different adipate dianion in cis coordination pattern with the metal center. Both the Complexes were crystallized in triclinic system, P-1 space group with cell parameters a = 6.8948(5), b = 10.7098(7), c = 12.4332(8) ?; α = 82.1120(10), β = 80.4950(10), γ = 72.9560(10)°, V = 861.87(10) ?³ for 1, a = 9.5058(6), b = 9.9341(7), c = 12.6460(8) ?; α = 70.5080(10), β = 73.5740(10), γ = 75.0720(10)°, V = 1062.05(12) ?³ for 2 respectively. Extensive hydrogen bonding interaction is observed between the lattice water molecules and the coordination network. Compound 2 is a layered architecture, where the neutral framework is constructed by two different adipate anions (in monoanionic and dianionic form) coordinating to the metal center. Interestingly, three water molecules present in the lattice of compound 2 are involved in hydrogen bonding network among themselves, creating a centro-symmetric hexameric water cluster composed of a tetracyclic ring with dangling water molecules attached at alternate positions of the rectangle, which interact with the carboxylate oxygen, thereby extending the hydrogen bonded water network.