Noncovalent-bonded 2D–3D Zn2+, Cd2+, and Cu2+ supramolecular coordination complexes with 2,2′-bipyridine and carboxylates: their synthesis and characterization

AbstractThe present report pertains to the synthesis and characterization of six mixed-ligand complexes of [Zn(L)(pip-)2] (1) (L = 2,2′-bipyridine, pip =1,3-benzodioxole-5-carboxylate), [Zn(L)(mpp–)2·H2O]·H2O (2) (mpp =2-methyl-2-phenoxypropanoate), [Cu(L)(mca–)2]·5H2O (3) (mca = p-methoxycinnamate), [Cd(L)( mca–)2·2H2O] (4), [Cd(L)2(mpp–)2]·H2O (5) and [Cu(L)(pdp2-)0.5Cl·H2O]2·8H2O (6) (pdp =1,4-piperazinedipropionate). The resulting complexes were characterized from EA, IR, and single-crystal XRD analysis. The TGA of all complexes were also evaluated. Compound 2 is a 2D sheet; all other complexes are 3D supramolecular assemblies. Zn and Cd have octahedral coordination geometry and Cu tetrahedral or square-pyramidal coordination.The single-crystal XRD studies showed that 1–5 are mononuclear, while 6 is a centrosymmetric dinuclear complex. The 2,2′-bipyridines are chelating bidentate to the metal ions. The COO– is monodentate in 2–6, while COO– in 1 has chelating bidentate coordination. The pyridine 3(3′)...