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摘要
Seven new complexes, namely Cd(Hdmpz)(2)(L1)(2) (1) (Hdmpz = 3,5-dimethylpyrazole, L1 = N-phenylmaleamate), Cd(Hdmpz)(4)(L2)(2) (2) (L2 = 1,3-benzodioxole-5-carboxylate), Zn-2(mu-dmpz)(2)(Hdmpz)(2)(L3)(2) (3) (L3 = 2-chloronicotinate), Zn(Hdmpz)(2)(L4)(2) (4) (L4 = 3,5-dinitrobenzoate), Zn(Hdmpz)(2)(HL5)(2) (5) (HL5 = 5-chlorosalicylate), Cd(Hdmpz)(2)(HL6) (6) (HL6 = 5-sulfosalicylate) and Cd-2(Hdmpz)(4)(L7)(2) (7) (L7 = maleate), have been synthesized from the self-assembly of the Zn/Cd ions, 3,5-dimethylpyrazole and carboxylate ligands at room temperature. All the complexes were structurally characterized by different techniques, including elemental analysis, IR spectra, TG and single crystal X-ray diffraction analysis. The X-ray studies suggest that these complexes display mononuclear to dinuclear structures with a tetrahedral geometry around each zinc center, and an octahedral geometry around each cadmium center. The pyrazole ligands in all the compounds except compound 3 are coordinated only in the monodentate fashion by its neutral N group. In 2, 3, 4, 5 and 6, the carboxylate groups behave as monodentate ligands. The COO- group in 1 and the SO3- group in 6 both coordinate to the metal in a chelating bidentate fashion. The carboxylates in 7 functioned as a tetradentate bridging ligand. The uncoordinated oxygen atom of the carboxylate group in all of the compounds forms intramolecular hydrogen bonds with the N-H group of the coordinated 3,5-dimethylpyrazole ligand. On the basis of the X-ray crystallographic study, the rich intra- and intermolecular non-covalent interactions, such as classical hydrogen bonds, CH-Cl, CH3-Cl, Cl center dot center dot center dot Cl, Cl center dot center dot center dot O, C-H center dot center dot center dot O, CH3 center dot center dot center dot O, C-H center dot center dot center dot pi, CH2 center dot center dot center dot pi, CH3-pi, O-pi and pi-pi interactions, are analyzed. The various non-bonding interactions in these compounds are responsible for different structures, such as sheet, 3D network and 3D layer structures. The thermal stabilities of 1-7 were examined and the results show that the complexes seem to be good candidates for novel hybrid inorganic-organic materials with good thermal stability.
