Construction of six non-covalent-bonded supramolecules from reactions of cadmium(II), and zinc(II) with 3,5-dimethylpyrazole and carboxylate ligands

Six new complexes Cd(Hdmpz)2(L1)2 (1) (Hdmpz = 3,5-dimethylpyrazole, L1 = nicotinate), Zn(Hdmpz)2(L2)2 (2) (L2 = N-phenylanthranilate), Zn(Hdmpz)2(L3)2 (3) (L3 = N-phenylmaleamate), Cd(Hdmpz)4(L4)2 (4) (L4 = 5-chlorosalicylate), Cd2(Hdmpz)6(L5)2Cd(Hdmpz)4(HL5)2·2H2O (5) (HL5 = hydrogen 1,4-cyclohexanedicarboxylate, L5 = 1,4-cyclohexanedicarboxylate), and Zn(Hdmpz)2(L6) (6) (L6 = sebacate) were prepared and characterized by elemental analysis, IR spectra, TG, and single crystal X-ray diffraction analysis. The X-ray studies revealed that these complexes display mononuclear to trinuclear structures with tetrahedral geometry around each zinc center, and octahedral geometry around each cadmium ion. The Hdmpzs in all compounds are coordinated only in monodentate fashion with its neutral N group. In all of the complexes except 5, all carboxylate groups behave as monodentate ligands. The uncoordinated O atom of the carboxylate group in 1, 2, 4, 5, and 6, forms intramolecular hydrogen bond with the N–H group of the Hdmpz. On the basis of X-ray crystallographic study the rich intra- and intermolecular non-covalent interactions such as classical hydrogen bonds, Cl⋯O, C–H⋯O, CH2⋯O, CH3⋯O, C–H⋯π, CH3–π, and π–π interactions are analyzed. The extensive nonbonding interactions in these compounds are responsible for different structures such as 3D network, 2D sheet, and 3D layer network structure.